Exhibit 99.1

TRICO BANCSHARES ANNOUNCES QUARTERLY RESULTS

CHICO, Calif. – (October 29, 2018) – TriCo Bancshares (NASDAQ: TCBK) (the “Company”), parent company of Tri Counties Bank, today announced net income of $16,170,000 for the quarter ended September 30, 2018, compared to $15,029,000 and $11,897,000 for the trailing quarter and the three months ended September 30, 2017, respectively. Diluted earnings per share were $0.53 for the quarter ended September 30, 2018, compared to $0.65 and $0.51 for the trailing quarter and three months ended September 30, 2017. The growth in net income as compared to the trailing quarter is primarily related to the acquisition of FNB Bancorp (“FNBB”) that was completed on July 6, 2018. In addition, the company continued to benefit from the reduction in Federal income tax rate which declined to 21% effective January 1, 2018 as compared to 35% in prior periods.

Financial Highlights

Performance highlights and other developments for the Company included the following:

President and CEO, Rick Smith commented; “This is an exciting time for Tri Counties Bank. Our entry to the San Francisco Peninsula, with the acquisition of twelve full service branches and an experienced management team from First National Bank of Northern California provides us new and expanded growth opportunities with both potential and existing relationships in that market. The pace of integration between Tri Counties Bank and First National Bank of Northern California demonstrates the commitment of personnel from both institutions to achieve success and also, the complimentary nature of the cultures that have been brought together. As of the end of the quarter, our acquisition related restructuring activities are nearly complete and the non-recurring costs associated with those activities are on track with budget. We look forward to realizing the synergies made possible by bringing a broader array of financial services with solutions to the deeply rooted relationships that were established during First National Bank’s 55 year history.”

Summary Results

The following is a summary of the components of the Company’s operating results and performance ratios for the periods indicated:

The following is a summary of certain of the Company’s consolidated assets and deposits as of the dates indicated:

Overall results for the three and nine months ended September 30, 2018 were primarily benefited by the acquisition of First National Bank of Northern California, the wholly owned subsidiary of FNB Bancorp, effective July 6, 2018. In connection with the acquisition and subsequent integration and restructuring, the Company incurred a variety of expenses. During the three and nine month periods ended September 30, 2018 total non-interest expenses increased by $10,156,000 and $14,462,000 as compared to the same periods in 2017. The non-recurring costs included in those increases were $4,150,000 and $5,227,000 for the three and nine months ended September 30, 2018.

In addition to the $834,683,000 in loans acquired, recorded net of a $33,417,000 discount, organic loan growth totaled $177,588,000 or an annualized rate of 7.9% during the first nine months of 2018.    In addition to the $991,935,000 in acquired deposits, organic deposit growth for the first nine months of 2018 was $92,051,000 or 3.1% on an annualized basis. Total assets acquired from FNB Bancorp totaled $1,306,539,000, inclusive of the core deposit intangible. Goodwill associated with the acquisition of FNB Bancorp was $156,661,000 and the core deposit intangible, which will be amortized over an estimated weighted average life of 6.2 years, was $27,605,000.

Net Interest Income and Net Interest Margin

The following is a summary of the components of net interest income for the periods indicated:

Loans may be acquired at a premium or discount to par value, in which case, the premium is amortized (subtracted from) or accreted (added to) interest income over the remaining life of the loan. Generally, as time goes on, the effects of loan discount accretion and loan premium amortization decrease as the purchased loans mature or pay off early. Upon the early pay off of a loan, any remaining (unaccreted) discount or (unamortized) premium is immediately taken into interest income; and as loan payoffs may vary significantly from quarter to quarter, so may the impact of discount accretion and premium amortization on interest income. During the three and nine months ended September 30, 2018 purchased loan discount accretion was $2,098,000 and $3,289,000; for the three and nine months ended September 30, 2017 purchased loan accretion was $1,364,000 and $5,075,000. The changes in volume of interest earning assets and interest bearing liabilities contributed an additional $15,937,000 in interest income while the changes in rates contributed $201,000 during the current quarter as compared to the quarter ended September 30, 2017. The decreases in Federal tax equivalent yield adjustment are due to the changes in tax rate changes which became effective on January 1, 2018 whereby the Federal tax rate was reduced from 35% to 21%.

The following table shows the components of net interest income and net interest margin on a fully tax-equivalent (FTE) basis for the periods indicated:

ANALYSIS OF CHANGE IN NET INTEREST MARGIN ON EARNING ASSETS

(unaudited, dollars in thousands)

Net interest income (FTE) during the three months ended September 30, 2018 increased $16,138,000 or 36.1% to $60,846,000 compared to $44,708,000 during the three months ended September 30, 2017. The increase in net interest income (FTE) was due primarily to an increase in the average balance of loans and a 9 basis point increase in yield on loans, which was partially offset due to an increase in the average balance of interest-bearing liabilities and a 17 basis point increase in the average rate paid on interest-bearing liabilities.

The index utilized in a significant portion of the Company’s variable rate loans, Wall Street Journal Prime, has increased by 1.00% to 5.25% at September 30, 2018 as compared to 4.25% at September 30, 2017. The 9 basis point increase in loan yields from 5.18% during the three months ended September 30, 2017 to 5.27% during the three months ended September 30, 2018 was primarily due to increases in market rates. More specifically, increases in purchased loan discount accretion between the three months ended September 30, 2018 and 2017 contributed to an increase net interest margin by only 2 basis points.    More importantly, yields on loans increased 21 basis points as compared to the prior quarter from 5.06% for the three months ended June 30, 2018 of which 14 basis points were contributed by increases in loan discount accretion and the remaining 7 basis points were contributed by changes in the coupon rate associated with loans. On their acquisition date, the weighted average coupon rate was 4.88% for loans acquired during the three month period ended September 30, 2018.

The increase in the average rate paid on interest-bearing liabilities for the trailing and comparable quarters of 8 basis points and 17 basis points, respectively, was due in part to differences in market rates associated with deposits acquired from First National Bank of Northern California and to increases in the variable rates paid on other borrowings and subordinated debt. The weighted average rate associated with interest bearing acquired deposits was 0.29% for non-time deposits and 0.92% for time deposits on the day of acquisition. The rate paid on other borrowings was 2.31% at September 30, 2018 as compared to 2.05% and 1.11% as of the trailing quarter and the same quarter in the prior year, respectively.

The following table shows the components of net interest income and net interest margin on a fully tax-equivalent (FTE) basis for the periods indicated:

ANALYSIS OF CHANGE IN NET INTEREST MARGIN ON EARNING ASSETS

(unaudited, dollars in thousands)

Net interest income (FTE) during the nine months ended September 30, 2018 increased $20,941,000 or 15.9% to $152,326,000 compared to $131,385,000 during the nine months ended September 30, 2017. The increase in net interest income (FTE) was due primarily to an increase in the average balance of loans, which was partially offset by an increase in the average balance of interest-bearing liabilities and a 13 basis point increase in the average rate paid on interest-bearing liabilities.

During the nine months ended September 30, 2018, the average balance of loans increased by $582,994,000 or 20.8% to $3,390,447,000. The increase in net interest income was partially offset by a decrease in the year-to-date purchased loan discount accretion from $5,075,000 during the nine months ended September 30, 2017 to $3,289,000 during the nine months ended September 30, 2018. This decrease in purchased loan discount accretion reduced loan yields by 11 basis points, and net interest margin by 7 basis points. The 13 basis point increase in the average rate paid on interest-bearing liabilities was primarily due to increases in market rates that increased the rates the Company pays on its time deposits, overnight borrowings, and junior subordinated debt.

Also affecting net interest margin during the three and nine months ended September 30, 2018, was the decrease in the Federal tax rate from 35% to 21%. This decrease in the Federal tax rate caused the fully tax-equivalent (FTE) yield on the Company’s nontaxable investments to decrease from 4.89% during the nine months ended September 30, 2017 to 3.99% during the nine months ended September 30, 2018.

Asset Quality and Loan Loss Provisioning

The Company recorded provisions for loan losses of $2,651,000 and $765,000 during the three months ended September 30, 2018 and 2017, respectively. While the Company did record net charge-offs of $572,000 during the third quarter of 2018 as compared to net charge-offs of $161,000 in the 2017 quarter, the primary cause for the increase in provision for loan losses was due to changes in the Company’s analysis of qualitative factors associated with the

California economy. More specifically, the Company has become more cautious about the risks associated with trends in California real estate prices and the decrease in affordability of housing in the markets served by the Company. Loan growth, excluding acquired loans, also contributed to the need for additional provisioning.

During the nine months ended September 30, 2018 the Company recorded a loan loss provision of $1,777,000 as compared to a reversal of provision for loan losses of $1,588,000 during the nine months ended September 30, 2017. Nonperforming loans were $27,148,000, or 0.67% of loans outstanding as of September 30, 2018, compared to $25,420,000, or 0.81% of loans outstanding as of June 30, 2018 and $24,394,000 or 0.81% of loans outstanding as of December 31, 2017. The fair value of loans acquired with deteriorated credit quality during the current quarter totaled $1,302,000.

The Company continued to experience improvement in the overall credit quality of its loan portfolio. At September 30, 2018 loans past due greater than thirty days totaled $13,218,000 or 0.33% of loans outstanding, as compared to $11,626,000 or 0.37% at June 30, 2018 and $11,609,000 or 0.39% at December 31, 2017. At September 30, 2018, classified loans totaled $45,548,000 (1.13% of total loans) compared to $44,202,000 (1.40%) and $53,593,000 (1.78%) at June 30, 2018 and December 31, 2017, respectively.

Non-interest Income

The following table presents the key components of noninterest income for the periods indicated:

Noninterest income decreased $744,000 (5.8%) to $12,186,000 during the three months ended September 30, 2018 compared to the three months ended September 30, 2017. The decrease in noninterest income was due to the changes noted in the table above. The decrease of $241,000 (26.3%) in other service fees was caused primarily by a decrease in merchant residual income due to the lagging effect of transitioning to a new processor, decreasing from $362,000 during the three months ended September 30, 2017 to $161,000 during the three months ended September 30, 2018. Gains from sales of investments securities decreased by $754,000 (78.5%) due to less sales activity during the three month period ending September 30, 2018. Offsetting the decreases in non-interest income was an increase of $288,000 (88.6%) in change in value of mortgage servicing rights (MSRs) due to slight decreases in estimated prepayment speeds during the three months ended September 30, 2018.

Noninterest income decreased $893,000 (2.4%) to $36,650,000 during the nine months ended September 30, 2018 compared to the nine months ended September 30, 2017. The decrease in noninterest income was due to the changes noted in the table above. The $695,000 (5.7%) decrease in service charges on deposit accounts was made up of a $688,000 (10%) decrease in nonsufficient fund (NSF) fees to $6,220,000, and a $7,000 (0.1%) decrease in other deposit account service charges to $5,188,000. The decrease in NSF fees was due primarily to continued growth in customer adoption of the Company’s digital services that improves the ability of customers to manage funds and avoid overdrafts. The decrease in other deposit service charges was due primarily to the rapid growth of customer adoption of e-Statements that reduces statement fees. While both of these revenue generating activities decreased, the Company has a net benefit through a reduction in actual operational costs. The decrease of $467,000 (18.5%) in other service fees was caused primarily by a decrease in merchant residual income due to the lagging effect of transitioning to a new processor, decreasing from $890,000 during the prior nine month period to $471,000 during the nine months ended September 30, 2018. Gains from sales of investments securities decreased by $754,000 (78.5%) due to less sales activity during the nine month period ending September 30, 2018. The $833,000 (104.8%) increase in change in value of mortgage servicing rights (MSRs) was due to slight decreases in prepayment speeds during the nine months ended September 30, 2018. During the nine months ended September 30, 2017, the Company recorded other non-interest income of $490,000 related to the termination of a loss sharing agreement with the FDIC.

Non-interest Expense

The following table presents the key components of the Company’s noninterest expense for the periods indicated:

Salary and benefit expenses increased $4,890,000 (23.4%) to $25,823,000 during the three months ended September 30, 2018 compared to $20,933,000 during the three months ended September 30, 2017. Base salaries, net of deferred loan origination costs increased $3,451,000 (25.4%) to $17,051,000. The increase in base salaries was primarily due to the additional full-time equivalent employees acquired with the FNBB merger. Average full-time equivalent employees increased by 153 or 15.4% during the comparable quarters. In addition, increases in base salaries due to annual merit increases and the addition of employees with base salaries above the average base salary also contributed to the increase. Commissions and incentive compensation increased $614,000 (23.5%) to $3,223,000 during the three months ended September 30, 2018 compared to the year-ago quarter. Benefits & other compensation expense increased $825,000 (17.5%) to $5,549,000 during the three months ended September 30, 2018 due primarily to the increase in full time equivalent employees and to a lesser extent an increase in health insurance expense. Severance and other merger related non-recurring compensation costs are included with “merger and acquisition expense” in the table above.

Other noninterest expense increased $5,266,000 (32.3%) to $21,555,000 during the three months ended September 30, 2018 compared to the three months ended September 30, 2017.    The increase in other noninterest expense was due to the changes noted in the table above. During the three months ended September 30, 2018, the Company incurred $4,150,000 of merger related expense associated with the merger with FNB Bancorp.

Salary and benefit expenses increased $6,608,000 (10.6%) to $68,928,000 during the nine months ended September 30, 2018 compared to $62,320,000 during the nine months ended September 30, 2017. Base salaries, net of deferred loan origination costs increased $4,795,000 (11.8%) to $45,442,000. The increase in base salaries was primarily due to the additional full-time equivalent employees acquired with the FNBB merger. Average full-time equivalent employees increased by 45 or 4.5% during the comparable nine month periods. In addition, increases in base salaries due to annual merit increases and the addition of employees with base salaries above the average base salary also contributed to the increase. Commissions and incentive compensation increased $854,000 (12.2%) to $7,834,000 during the nine months ended September 30, 2018 compared to the prior year-to-date period. Benefits & other compensation expense increased $959,000 (6.5%) to $15,652,000 during the nine months ended September 30, 2018 due primarily to the increase in full time equivalent employees and to a lesser extent an increase in health insurance expense.

Other noninterest expense increased $7,854,000 (16.8%) to $54,482,000 during the nine months ended September 30, 2018 compared to the nine months ended September 30, 2017.    The increase in other noninterest expense was due to the changes noted in the table above. During the nine months ended September 30, 2018, the Company incurred $5,227,000 of merger related expense associated with the merger with FNB Bancorp.

Balance Sheet

In addition to the balance sheet changes which resulted from the acquisition of FNB Bancorp, total assets grew by $199,231,000 between September 2017 and September 2018. This growth was led by $261,140,000 related to organic loan growth which was funded by $31,473,000 in normally scheduled payments on investment securities, $173,726,000 in organic deposit growth and an increase in other borrowings of $19,101,000. Total equity increased to $802,115,000 at September 30, 2018 as compared to $512,344,000 at the close of the trailing quarter and inclusive of $26,959,000 and $21,123,000 in accumulated other comprehensive loss at the same periods. As a result the Company’s book value per share increased to $26.37 from $22.27 per share at June 30, 2018. Based on a net increase in intangible assets of $182,876,000 and an increase in total shares outstanding of 7,413,655, the Company’s tangible book value decreased to $18.10 per share from $19.28 per share at June 30, 2018.

About TriCo Bancshares

Established in 1975, Tri Counties Bank is a wholly-owned subsidiary of TriCo Bancshares (NASDAQ: TCBK) headquartered in Chico, California, providing a unique brand of customer Service with Solutions available in traditional stand-alone and in-store bank branches in communities throughout Northern and Central California. Tri Counties Bank provides an extensive and competitive breadth of consumer, small business and commercial banking financial services, along with convenient around-the-clock ATM, online and mobile banking access. Brokerage services are provided by the Bank’s investment services through affiliation with Raymond James Financial Services, Inc. Visit www.TriCountiesBank.com to learn more.

Forward-Looking Statement

The statements contained herein that are not historical facts are forward-looking statements based on management’s current expectations and beliefs concerning future developments and their potential effects on the Company. Such statements involve inherent risks and uncertainties, many of which are difficult to predict and are generally beyond our control. There can be no assurance that future developments affecting us will be the same as those anticipated by management. We caution readers that a number of important factors could cause actual results to differ materially from those expressed in, or implied or projected by, such forward-looking statements. These risks and uncertainties include, but are not limited to, the following: the strength of the United States economy in general and the strength of the local economies in which we conduct operations; the effects of, and changes in, trade, monetary and fiscal policies and laws, including interest rate policies of the Board of Governors of the Federal Reserve System; inflation, interest rate, market and monetary fluctuations; the impact of changes in financial services policies, laws and regulations; technological changes; mergers and acquisitions; changes in the level of our nonperforming assets and charge-offs; any deterioration in values of California real estate, both residential and commercial; the effect of changes in accounting standards and practices; possible other-than-temporary impairment of securities held by us; changes in consumer spending, borrowing and savings habits; our ability to attract deposits and other sources of liquidity; changes in the financial performance and/or condition of our borrowers; the impact of competition from other financial service providers; the possibility that any of the anticipated benefits of our recent merger with FNBB will not be realized or will not be realized within the expected time period, or that integration of FNBB’s operations will be more costly or difficult than expected; the challenges of integrating and retaining key employees; unanticipated regulatory or judicial proceedings; the costs and effects of litigation and of unexpected or adverse outcomes in such litigation; and our ability to manage the risks involved in the foregoing. Additional factors that could cause results to differ materially from those described above can be found in our Annual Report on Form 10-K for the year ended December 31, 2017, which is on file with the Securities and Exchange Commission (the “SEC”) and available in the “Investor Relations” section of our website, https://www.tcbk.com/investor-relations and in other documents we file with the SEC. Annualized, pro forma, projections and estimates are not forecasts and may not reflect actual results.

TRICO BANCSHARES - CONSOLIDATED FINANCIAL DATA

(Unaudited. Dollars in thousands, except share data)