Exhibit 99.1

FOR IMMEDIATE RELEASE

PROSPERITY BANCSHARES, INC.^®

REPORTS THIRD QUARTER

2016 EARNINGS

HOUSTON, October 26, 2016. Prosperity Bancshares, Inc.^® (NYSE: PB), the parent company of Prosperity Bank^® (collectively, “Prosperity”), reported net income for the quarter ended September 30, 2016 of $68.651 million or $0.99 per diluted common share. Additionally, nonperforming assets remain low at 0.32% of third quarter average earning assets.

“I am pleased to share the positive earnings we had for the third quarter of 2016. We showed impressive annualized returns on third quarter average tangible common equity of 16.79% and on third quarter average assets of 1.27%.   I am also excited to announce that our Board raised the dividend to $0.34 per share for the fourth quarter 2016, an increase of 13.33%.  The increased dividend reflects the continued confidence we have in our company,” said David Zalman, Prosperity’s Chairman and Chief Executive Officer.    

“Job creation in Texas has continued despite the challenges in the oil and gas industry.  The Department of Labor reported last week that Texas added 38,300 jobs in September and the Federal Reserve Bank of Dallas projected 1.2% overall employment growth for Texas for 2016.  Also, the number of operating rigs grew to 553 last week from a low of 404 in May 2016,” continued Zalman.

“As mentioned in our prior earnings release, there are certain areas of Texas that have performed better than other areas more directly impacted by the downturn in the oil and gas industry as well as decreased agricultural prices. Our wide footprint throughout the State has helped to minimize the effects of the lower performing areas.  We believe that our loan growth at September 30, 2016 compared with September 30, 2015, while modest, along with our excellent credit quality, was positive given the economic challenges in Texas as well as Oklahoma,” added Zalman.

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“We are very optimistic about our company’s future.  We believe that the hard work of our entire team will help our customers grow and in turn increase shareholder value.  We will continue to focus on running one of the most efficient banks in the country, maintaining our solid asset quality and enhancing shareholder value,” concluded Zalman.

Results of Operations for the Three Months Ended September 30, 2016

Net income was $68.651 million for the three months ended September 30, 2016 compared with $70.598 million for the same period in 2015. Net income per diluted common share was $0.99 for the three months ended September 30, 2016 compared with $1.01 for the same period in 2015. Net income (excluding purchase accounting adjustments) was $63.855 million for the three months ended September 30, 2016 compared with $64.154 million for the three months ended September 30, 2015. Net income per diluted common share (excluding purchase accounting adjustments) was $0.92 for the three months ended September 30, 2016 and 2015. The reconciliation of these non-GAAP financial measures is shown on page 12.  Annualized returns on average assets, average common equity and average tangible common equity for the three months ended September 30, 2016 were 1.27%, 7.66% and 16.79%⁽¹⁾, respectively.  Prosperity’s efficiency ratio (excluding credit loss provisions, net gains and losses on the sale of assets and taxes) was 43.26% for the three months ended September 30, 2016.

Net interest income before provision for credit losses for the three months ended September 30, 2016 was $154.064 million compared with $156.108 million during the same period in 2015, a decrease of $2.044 million or 1.3%. This change was primarily due to a decrease in loan discount accretion of $3.414 million for the three months ended September 30, 2016. Linked quarter net interest income before provision for credit losses decreased $4.403 million to $154.064 million compared with $158.467 million during the three months ended June 30, 2016, primarily due to a decrease in average interest-earning assets of 1.5% and a decrease in loan discount accretion of $1.684 million.

The net interest margin on a tax equivalent basis was 3.29% for the three months ended September 30, 2016, compared with 3.30% for the same period in 2015 and 3.37% for the three months ended June 30, 2016. This change was primarily due to a decrease in loan discount accretion of $1.684 million and a decrease in average yield on interest-earning assets of 9 basis points for the three months ended September 30, 2016. Excluding purchase accounting adjustments, the net interest margin on a tax equivalent basis was 3.14% for the three months ended September 30, 2016, compared with 3.10% for the same period in 2015 and 3.19% for the three months ended June 30, 2016. The reconciliation of these non-GAAP financial measures is shown on page 12.

Noninterest income was $29.684 million for the three months ended September 30, 2016 compared with $31.780 million for the same period in 2015, a decrease of $2.096 million or 6.6%. This change was primarily due to a decrease in brokerage income, NSF fees and other noninterest income. On a linked quarter basis, noninterest income increased $1.211 million or 4.3% compared with the quarter ended June 30, 2016. This change was primarily due to an increase in NSF fees, mortgage income and other noninterest income.

Noninterest expense was $79.476 million for the three months ended September 30, 2016 compared with $76.430 million for the same period in 2015, an increase of $3.046 million or 4.0%. This change was primarily due to an increase in salaries and benefits expense and other noninterest expense.

Results of Operations for the Nine Months Ended September 30, 2016

Net income was $205.673 million for the nine months ended September 30, 2016 compared with $216.171 million for the same period in 2015.  Net income per diluted common share was $2.95 for the nine months ended September 30, 2016 compared with $3.09 for the same period in 2015. Net income (excluding purchase accounting adjustments) was $186.453 million for the nine months ended September 30, 2016 compared with $189.332 million for the nine months ended September 30, 2015. Net income per diluted common share (excluding purchase accounting adjustments) was $2.67 for the nine months ended September 30, 2016 compared with $2.71 for the nine months ended September 30, 2015. The reconciliation of these non-GAAP financial measures is shown on page 12. Annualized returns on average assets, average common equity and average tangible common equity for the nine months ended September 30, 2016 were 1.25%, 7.74% and 17.17%⁽¹⁾, respectively.  Prosperity’s efficiency ratio (excluding credit loss provisions, net gains and losses on the sale of assets and taxes) was 42.24% for the nine months ended September 30, 2016.

Net interest income before provision for credit losses for the nine months ended September 30, 2016 was $478.788 million compared with $477.252 million for the same period in 2015, an increase of $1.536 million or 0.3%. This change was primarily due to a 1.6% increase in average interest-earning assets, which was partially offset by a decrease in loan discount accretion of $12.865 million for the nine months ended September 30, 2016.The net interest margin on a tax equivalent basis for the nine months ended September 30, 2016 was 3.38% compared with 3.42% for the same period in 2015. This change was primarily due to the decrease in loan discount accretion. Excluding purchase accounting adjustments, the net interest margin on a tax equivalent basis was 3.18% for the nine months ended September 30, 2016 compared with 3.13% for the same period in 2015. The reconciliation of these non-GAAP financial measures is shown on page 12.

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Noninterest income was $88.950 million for the nine months ended September 30, 2016 compared with $90.498 million for the same period in 2015, a decrease of $1.548 million or 1.7%. This change was primarily due to a decrease in brokerage income, net gain on sale of assets and other noninterest income, which was partially offset by an increase in service charges on deposit accounts and mortgage income for the nine months ended September 30, 2016.

Noninterest expense was $239.239 million for the nine months ended September 30, 2016 compared with $235.627 million for the same period in 2015, an increase of $3.612 million or 1.5%.  This change was primarily due to an increase in salaries and benefits expense, software amortization and other noninterest expense, which was partially offset by a decrease in FDIC assessments for the nine months ended September 30, 2016. One-time pretax merger related expenses of $663 thousand related to the Tradition acquisition were recorded during the nine months ended September 30, 2016.

Balance Sheet Information

At September 30, 2016, Prosperity had $21.404 billion in total assets, a decrease of $163.192 million or 0.8%, compared with $21.567 billion at September 30, 2015.

Loans at September 30, 2016 were $9.548 billion, an increase of $343.326 million or 3.7%, compared with $9.205 billion at September 30, 2015. Linked quarter loans decreased $101.694 million or 1.1% from $9.650 billion at June 30, 2016.

As part of its commercial and industrial lending activities, Prosperity extends credit to oil and gas production and service companies. Oil and gas production loans are loans to companies directly involved in the exploration and/or production of oil and gas. Oil and gas service loans are loans to companies that provide services for oil and gas production and exploration. At September 30, 2016, oil and gas loans totaled $308.951 million or 3.2% of total loans, of which $139.913 million were to production companies and $169.038 million were to service companies. This compares with total oil and gas loans of $405.176 million or 4.4% of total loans at September 30, 2015, of which $185.162 million were to production companies and $220.014 million were to service companies. On a linked quarter basis, oil and gas loans decreased $19.458 million, from $328.409 million or 3.4% of total loans at June 30, 2016, of which $156.734 million were production loans and $171.675 million were service loans.

Deposits at September 30, 2016 were $16.921 billion, a decrease of $18.528 million or 0.1%, compared with $16.940 billion at September 30, 2015. Linked quarter deposits decreased $297.736 million or 1.7% from $17.219 billion at June 30, 2016. The decrease primarily resulted from a seasonal decrease in deposit balances for Prosperity’s over 400 public fund customers and the planned decrease in higher rate brokered deposits.

The table below provides detail on the impact of loans acquired and deposits assumed in the acquisition of Tradition completed on January 1, 2016:

Excluding loans acquired in the Tradition acquisition and new production at the acquired banking centers since the acquisition date, loans at September 30, 2016 increased $114.969 million or 1.2% compared with September 30, 2015 and, on a linked quarter basis, decreased $96.711 million or 1.0%.

Excluding deposits assumed in the Tradition acquisition and new deposits generated at the acquired banking centers since the acquisition date, deposits at September 30, 2016 decreased $451.386 million or 2.7% compared with September 30, 2015 and, on a linked quarter basis, decreased $290.484 million or 1.7%.

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Asset Quality

Nonperforming assets totaled $60.166 million or 0.32% of quarterly average interest-earning assets at September 30, 2016, compared with $48.628 million or 0.26% of quarterly average interest-earning assets at September 30, 2015, and $52.130 million or 0.27% of quarterly average interest-earning assets at June 30, 2016.

The allowance for credit losses was $85.585 million or 0.90% of total loans at September 30, 2016, 0.88% of total loans at September 30, 2015 and 0.87% of total loans at June 30, 2016.  Excluding loans acquired that are accounted for under FASB Accounting Standards Codification (“ASC”) Topics 310-20 and 310-30, the allowance for credit losses was 1.03% of remaining loans as of September 30, 2016, compared with 1.06% at September 30, 2015 and 1.01% at June 30, 2016⁽¹⁾.

The provision for credit losses was $2.000 million for the three months ended September 30, 2016 compared with $5.310 million for the three months ended September 30, 2015 and $6.000 million for the three months ended June 30, 2016.  The provision for credit losses was $22.000 million for the nine months ended September 30, 2016 compared with $7.060 million for the nine months ended September 30, 2015.

Net charge-offs were $241 thousand for the three months ended September 30, 2016 compared with $5.279 million for the three months ended September 30, 2015 and $5.888 million for the three months ended June 30, 2016. Net charge-offs were $17.799 million for the nine months ended September 30, 2016 compared with $6.819 million for the nine months ended September 30, 2015.

Conference Call

Prosperity’s management team will host a conference call on Wednesday, October 26, 2016 at 10:30 a.m. Eastern Time (9:30 a.m. Central Time) to discuss Prosperity’s third quarter 2016 earnings. Individuals and investment professionals may participate in the call by dialing 877-883-0383. The elite entry number is 8788636.

Alternatively, individuals may listen to the live webcast of the presentation by visiting Prosperity’s website at www.prosperitybankusa.com.  The webcast may be accessed from Prosperity’s home page by selecting “Presentations & Calls” from the drop-down menu on the Investor Relations tab and following the instructions.

Non-GAAP Financial Measures

Prosperity’s management uses certain non−GAAP financial measures to evaluate its performance. Specifically, Prosperity reviews tangible book value per share, return on average tangible common equity and the tangible equity to tangible assets ratio.  Further, as a result of acquisitions and the related purchase accounting adjustments, Prosperity uses certain non-GAAP measures and ratios that exclude the impact of these items to evaluate its net income and earnings per share (excluding purchase accounting adjustments) and its allowance for credit losses to total loans (excluding acquired loans accounted for under ASC Topics 310-20, “Receivables-Nonrefundable Fees and Other Costs” and 310-30, “Receivables-Loans and Debt Securities Acquired with Deteriorated Credit Quality”).  Prosperity believes these non-GAAP financial measures provide information useful to investors in understanding Prosperity’s financial results and Prosperity believes that its presentation, together with the accompanying reconciliations, provides a complete understanding of factors and trends affecting Prosperity’s business and allows investors to view performance in a manner similar to management, the entire financial services sector, bank stock analysts and bank regulators. Further, Prosperity believes that these non-GAAP measures provide useful information by excluding certain items that may not be indicative of its core operating earnings and business outlook.  These non-GAAP measures should not be considered a substitute for, nor of greater importance than, GAAP basis measures and results; Prosperity strongly encourages investors to review its consolidated financial statements in their entirety and not to rely on any single financial measure. Because non-GAAP financial measures are not standardized, it may not be possible to compare these financial measures with other companies’ non-GAAP financial measures having the same or similar names. Please refer to page 12 and the “Notes to Selected Financial Data” at the end of this Earnings Release for a reconciliation of these non-GAAP financial measures.

Dividend

Prosperity Bancshares, Inc. (“Prosperity Bancshares”) declared a fourth quarter cash dividend of $0.34 per share, to be paid on January 3, 2017 to all shareholders of record as of December 16, 2016, an increase of 13.33% compared with the third quarter 2016 dividend.

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Stock Repurchase Program

On January 27, 2016, Prosperity Bancshares announced a stock repurchase program under which up to 5%, or approximately 3.54 million shares, of its outstanding common stock may be acquired over the next twelve months at the discretion of management. As of September 30, 2016, Prosperity Bancshares had repurchased an aggregate of 1.24 million shares of its common stock under this program at an average weighted average price of $40.98 per share. During the third quarter of 2016, Prosperity Bancshares did not repurchase shares of its common stock. 

Acquisition of Tradition Bancshares, Inc.

On January 1, 2016, Prosperity Bancshares completed the acquisition of Tradition Bancshares, Inc. and its wholly-owned subsidiary Tradition Bank headquartered in Houston, Texas. Tradition Bank operated 7 banking offices in the Houston, Texas area, including its main office in Bellaire, 3 banking centers in Katy and 1 banking center in The Woodlands. As of December 31, 2015, Tradition Bancshares, Inc., on a consolidated basis, reported total assets of $547.963 million, total loans of $253.315 million, total deposits of $488.928 million and shareholders’ equity of $43.103 million.

Under the terms of the definitive agreement, Prosperity Bancshares issued 679,528 shares of Prosperity Bancshares common stock plus $39.0 million in cash for all outstanding shares of Tradition Bancshares, Inc. capital stock.

Prosperity Bancshares, Inc. ®

As of September 30, 2016, Prosperity Bancshares, Inc. ^® is a $21.404 billion Houston, Texas based regional financial holding company, formed in 1983. Operating under a community banking philosophy and seeking to develop broad customer relationships based on service and convenience, Prosperity offers a variety of traditional loan and deposit products to its customers, which consist primarily of small and medium sized businesses and consumers. In addition to established banking products, Prosperity offers a complete line of services including: Internet Banking services at www.prosperitybankusa.com, Retail Brokerage Services, Credit Cards, MasterMoney Debit Cards, 24 hour voice response banking, Trust and Wealth Management, Mortgage Services, Cash Management and Mobile Banking.

Prosperity currently operates 245 full-service banking locations: 65 in the Houston area, including The Woodlands; 29 in the South Texas area including Corpus Christi and Victoria; 36 in the Dallas/Fort Worth area; 22 in the East Texas area; 29 in the Central Texas area including Austin and San Antonio; 34 in the West Texas area including Lubbock, Midland-Odessa and Abilene; 16 in the Bryan/College Station area, 6 in the Central Oklahoma area and 8 in the Tulsa, Oklahoma area.

“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: This release contains, and the remarks by Prosperity’s management on the conference call may contain, forward-looking statements within the meaning of the securities laws that are based on current expectations, assumptions, estimates and projections about Prosperity Bancshares and its subsidiaries.  These forward-looking statements are not guarantees of future performance and are subject to risks and uncertainties, many of which are outside of Prosperity’s control, which may cause actual results to differ materially from those expressed or implied by the forward-looking statements.  These risks and uncertainties include but are not limited to whether Prosperity can: successfully identify acquisition targets and integrate the businesses of acquired companies and banks; continue to sustain its current internal growth rate or total growth rate; provide products and services that appeal to its customers; continue to have access to debt and equity capital markets; and achieve its sales objectives.  Other risks include, but are not limited to: the possibility that credit quality could deteriorate; actions of competitors; changes in laws and regulations (including changes in governmental interpretations of regulations and changes in accounting standards); a deterioration or downgrade in the credit quality and credit agency ratings of the securities in Prosperity’s securities portfolio; customer and consumer demand, including customer and consumer response to marketing; effectiveness of spending, investments or programs; fluctuations in the cost and availability of supply chain resources; economic conditions, including currency rate, interest rate and commodity price fluctuations; and weather.  These and various other factors are discussed in Prosperity Bancshares’ Annual Report on Form 10-K for the year ended December 31, 2015 and other reports and statements Prosperity Bancshares has filed with the SEC. Copies of the SEC filings for Prosperity Bancshares^® may be downloaded from the Internet at no charge from http://www.prosperitybankusa.com.

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Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(A) Includes $2,310, $2,496, $3,286, $3,138 and $3,788 in unrealized gains on available for sale securities for the quarterly periods ended September 30, 2016, June 30, 2016, March 31, 2016, December 31, 2015 and September 30, 2015, respectively.

(B) Includes $1,502, $1,623, $2,136, $2,040 and $2,462 in after-tax unrealized gains on available for sale securities for the quarterly periods ended September 30, 2016, June 30, 2016, March 31, 2016, December 31, 2015 and September 30, 2015, respectively.

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Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(In thousands)

(C) Interest income on securities was reduced by net premium amortization of $11,312, $10,407, $10,253, $13,775 and $14,845 for the three-month periods ended September 30, 2016, June 30, 2016, March 31, 2016, December 31, 2015 and September 30, 2015, and $31,972 and $44,455 for the nine-month periods ended September 30, 2016 and September 30, 2015, respectively.

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Prosperity Bancshares, Inc. ^®

Financial Highlights (Unaudited)

(Dollars and share amounts in thousands, except per share data and market prices)

(D) Interim periods annualized.

(E) Refer to the "Notes to Selected Financial Data" at the end of this Earnings Release for a reconciliation of this non-GAAP financial measure.

(F) Net interest margin for all periods presented is based on average balances on an actual 365 day or 366 day basis.

(G) Calculated by dividing total noninterest expense, excluding credit loss provisions, by net interest income plus noninterest income, excluding net gains and losses on the sale of assets.  Additionally, taxes are not part of this calculation.

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Prosperity Bancshares, Inc.^®

Financial Highlights (Unaudited)

(Dollars in thousands)