Exhibit 99.1

STONE ENERGY CORPORATION

Announces Second Quarter 2013 Results

LAFAYETTE, LA. August 5, 2013

Stone Energy Corporation (NYSE: SGY) today announced financial and operational results for the second quarter of 2013 and provided updated guidance. Some of the highlights include:

Chairman, President and Chief Executive Officer David Welch stated, “We continue to see the benefit of our strategy to transition from our legacy conventional shelf Gulf of Mexico assets to the higher potential Marcellus shale and GOM deep water. During the second quarter, average production increased to 272 MMcfe per day with the Marcellus shale contributing over 75 MMcfe per day and 16—18 additional wells expected to be brought on production during the second half of 2013. In the deep water, we expect to spud Stone’s first deep water operated well and participate in 2 to 3 non-operated deep water tests in the second half of 2013 as well as having a very exciting portfolio of deep water wells for 2014. With the success in Appalachia and the significant increased activity level in the deep water, we have engaged a financial advisor to market a portion of our conventional shelf, state water and onshore properties. This action is consistent with our long term strategy and will further increase our focus on the higher potential growth areas of the company.”

Financial Results

For the second quarter of 2013, Stone reported net income of $39.0 million, or $0.78 per share, on oil and gas revenue of $243.5 million, compared to net income of $30.5 million, or $0.62 per share, on oil and gas revenue of $220.2 million for the second quarter of 2012. Discretionary cash flow totaled $169.6 million during the second quarter of 2013, as compared to $147.1 million during the second quarter of 2012. Please see “Non-GAAP Financial Measures” and the accompanying financial statements for a reconciliation of discretionary cash flow, a non-GAAP financial measure, to net cash flow provided by operating activities.

Net daily production during the second quarter of 2013 averaged 45.4 thousand barrels of oil equivalent (MBoe) per day (272 million cubic feet of gas equivalent (MMcfe) per day), compared with net daily production of 40.1 MBoe (241 MMcfe) per day in the first quarter of 2013, and net daily production of 40.5 MBoe (243 MMcfe) per day in the second quarter of 2012. The production mix for the second quarter of 2013 was 43% oil, 10% natural gas liquids (NGL) and 47% natural gas.

Prices realized during the second quarter of 2013 averaged $104.41 per barrel of oil, $27.52 per barrel of NGLs and $4.07 per Mcf of natural gas. Average realized prices for the second quarter of 2012 were $107.74 per barrel of oil, $39.00 per barrel of NGLs and $2.70 per Mcf of natural gas. Effective hedging transactions increased the average realized price of natural gas by $0.17 per Mcf and increased the average realized price of oil by $3.02 per barrel in the second quarter of 2013.

Lease operating expenses during the second quarter of 2013 totaled $50.5 million ($12.23 per Boe or $2.04 per Mcfe), compared to $51.6 million ($14.01 per Boe or $2.33 per Mcfe), in the second quarter of 2012.

Depreciation, depletion and amortization (DD&A) on oil and gas properties for the second quarter of 2013 totaled $86.3 million ($20.88 per Boe or $3.48 per Mcfe), compared to $86.4 million ($23.46 per Boe or $3.91 per Mcfe) in the second quarter of 2012.

Salaries, general and administrative (SG&A) expenses (excluding incentive compensation expense) for the second quarter of 2013 were $15.2 million ($3.68 per Boe or $0.61 per Mcfe), compared to $13.1 million ($3.57 per Boe or $0.60 per Mcfe) in the second quarter of 2012.

Capital expenditures before capitalized SG&A and interest during the second quarter of 2013 were approximately $190.4 million, which include $22.5 million of plugging and abandonment expenditures. Additionally, $7.5 million of SG&A expenses and $10.9 million of interest were capitalized during the quarter. During the six months ended June 30, 2013, capital expenditures before capitalized SG&A and interest were approximately $325.8 million, which include $37.3 million of plugging and abandonment expenditures.

As of June 30, 2013 and August 5, 2013, we had no outstanding borrowings under our bank credit facility. In addition, Stone had letters of credit totaling $21.5 million, resulting in $378.5 million available for borrowing based on a borrowing base of $400 million.

Operational Update

Mississippi Canyon 26 – Amethyst (Deep Water). The deep water Amethyst exploration well is currently scheduled to spud in the fourth quarter of 2013. Stone is the operator of the well and currently holds a 100% working interest, although expects to reduce its working interest in the prospect. The well is estimated to take three months to drill.

Pompano Area – Cardona and Cardona South Prospects (Deep Water). Drilling on Stone’s Cardona prospect, located in Mississippi Canyon 29, is expected to commence during the first quarter of 2014 followed by the drilling of the Cardona South well. Stone plans to tie back both wells to the 100% owned Pompano platform with production projected for early 2015. Stone holds a 65% working interest in the Cardona wells and will be the operator. Each well is estimated to take three to four months to drill.

Mississippi Canyon 816 – Taggart (Deep Water). The deep water Taggart exploration well is currently planned to spud in the third quarter of 2013. Stone currently holds a 23% working interest in the prospect, which is operated by LLOG. The well is estimated to take two months to drill.

Mississippi Canyon 983 – San Marcos (Deep Water). The deep water San Marcos exploration well is currently scheduled to spud late in the third quarter of 2013. Stone currently holds a 25% working interest in the prospect, which is operated by Apache Deepwater LLC. The well is estimated to take four months to drill.

Mississippi Canyon 555 – Guadalupe (Deep Water). The deep water Guadalupe exploration well is currently scheduled to spud in late 2013 or early 2014. Stone currently holds a 40% working interest in the prospect, which is operated by Apache Deepwater LLC. The well is estimated to take four months to drill.

Walker Ridge 719 – Phinisi (Deep Water). The deep water Phinisi exploration well is projected to spud either in the fourth quarter of 2013 or the first half of 2014. Stone currently holds a 20% working interest in the prospect, which is operated by ENI. The well is estimated to take four months to drill.

La Cantera (Deep Gas). The third well in the La Cantera field, the Broussard #1 ST #1, was completed and placed on production in June 2013. The well is currently producing approximately 30 MMcfe per day. Combined with the first two wells, current gross production from this field is over 120 MMcfe per day (over 30 MMcfe per day net). Stone holds a 34.6% non-operated working interest in the field.

Appalachian Basin – Marcellus Shale (Drill Program Update). Stone drilled six Marcellus shale wells during the second quarter of 2013 bringing the total to 16 horizontal Marcellus shale wells drilled in the first half of 2013. Stone expects to drill 28 to 30 Marcellus shale wells during 2013. In addition, Stone completed seven Marcellus shale wells during the second quarter of 2013 bringing the total to 15 for the first half of 2013. Stone plans to complete 26 to 30 wells Marcellus shale wells in 2013.

Appalachian Basin – Marcellus Shale (Production Update). During the second quarter of 2013, Stone averaged 75 MMcfe per day (51 MMcf per day of gas and 4,000 barrels per day of liquids) from Stone’s Marcellus shale position. The Williams pipeline, which impacted first quarter volumes, was repaired and pressure restrictions were eliminated, which allowed Stone to restore shut-in production in the Mary field. In addition, 14 wells (11 new and 3 shut-in) in the Heather field were brought online during the second quarter of 2013. Stone expects to bring an additional 16-18 wells in the Mary field online during the second half of 2013.

Appalachian Basin – Upper Devonian Shale. Stone drilled an Upper Devonian horizontal test well in the Mary field during the second quarter of 2013. The well was drilled with a 2,450 foot lateral and completed with 9 stages. The well is expected to be tested and brought online late in 2013.

Conventional Shelf (Drill Program). The Hyena prospect in the Clovelly field in South Louisiana was drilled and completed in the second quarter. Current production from the Hyena well is approximately 300 barrels of oil per day. The ENSCO 81 jack-up rig is drilling on the second well of a four well drilling program that was initiated in May 2013. The Hammerlock prospect located on South Timbalier 100 was found non-productive and abandoned. The second well, the Ship Shoal 113 field Taildancer oil prospect, is currently drilling and is expected to be brought on line in the fourth quarter of 2013. The final two wells of the program are expected to be drilled in the Ship Shoal 113 field during the second half of 2013. In addition, Stone completed hydraulic rig operations on the Main Pass Block 288 A-26 sidetrack #1 well, which is currently producing approximately 400 barrels of oil per day.

Conventional Shelf (Potential Sale). Stone has engaged a financial advisor to market certain of its properties in the Conventional Shelf, state waters, and onshore Louisiana. The potential sale of these properties is subject to market conditions, and there is no assurance that it will be completed, in whole or in part, or by any particular time.

2013 Guidance

Guidance for the third quarter and full year 2013 is shown in the table below (updated guidance numbers are italicized and bolded). The guidance is subject to all the cautionary statements and limitations described below and under the caption “Forward Looking Statements.”

Hedge Position

The following table illustrates our derivative positions for 2013, 2014 and 2015 as of August 5, 2013:

Other Information

Stone Energy has planned a conference call for 9:00 a.m. Central Time on Tuesday, August 6, 2013 to discuss the operational and financial results for the second quarter of 2013. Anyone wishing to participate should visit our website at www.StoneEnergy.com for a live web cast or dial 1-877-228-3598 and request the “Stone Energy Call.” If you are unable to participate in the original conference call, a replay will be available immediately following the completion of the call on Stone Energy’s website. The replay will be available for one month.

Non-GAAP Financial Measures

In this press release, we refer to a non-GAAP financial measure we call “discretionary cash flow.” Management believes discretionary cash flow is a financial indicator of our company’s ability to internally fund capital expenditures and service debt. Management also believes this non-GAAP financial measure of cash flow is useful information to investors because it is widely used by professional research analysts in the valuation, comparison, rating and investment recommendations of companies in the oil and gas exploration and production industry. Discretionary cash flow should not be considered an alternative to net cash provided by operating activities or net income, as defined by GAAP. Please see the “Reconciliation of Non-GAAP Financial Measure” for a reconciliation of discretionary cash flow to cash flow provided by operating activities.

Forward Looking Statements

Certain statements in this press release are forward-looking and are based upon Stone’s current belief as to the outcome and timing of future events. All statements, other than statements of historical facts, that address activities that Stone plans, expects, believes, projects, estimates or anticipates will, should or may occur in the future, including future production of oil and gas, future capital expenditures and drilling of wells, future financial or operating results and the amount, and timing of any potential divestitures are forward-looking statements. Important factors that could cause actual results to differ materially from those in the forward-looking statements herein include the timing and extent of changes in commodity prices for oil and gas, operating risks, liquidity risks, political and regulatory developments and legislation, including developments and legislation relating to our operations in the Gulf of Mexico and Appalachia, market conditions relating to acquisitions and divestitures and other risk factors and known trends and uncertainties as described in Stone’s Annual Report on Form 10-K and Quarterly Reports on Form 10-Q as filed with the SEC. Should one or more of these risks or uncertainties occur, or should underlying assumptions prove incorrect, Stone’s actual results and plans could differ materially from those expressed in the forward-looking statements.

Estimates for Stone’s future production volumes are based on assumptions of capital expenditure levels and the assumption that market demand and prices for oil and gas will continue at levels that allow for economic production of these products. The production, transportation and marketing of oil and gas are subject to disruption due to transportation and processing availability, mechanical failure, human error, hurricanes and numerous other factors. Stone’s estimates are based on certain other assumptions, such as well performance, which may vary significantly from those assumed. Delays experienced in well permitting could affect the timing of drilling and production. Lease operating expenses, which include major maintenance costs, vary in response to changes in prices of services and materials used in the operation of our properties and the amount of maintenance activity required. Estimates of DD&A rates can vary according to reserve additions, capital expenditures, future development costs, and other factors. Therefore, we can give no assurance that our future production volumes, lease operating expenses or DD&A rates will be as estimated.

Stone Energy is an independent oil and natural gas exploration and production company headquartered in Lafayette, Louisiana with additional offices in New Orleans, Houston and Morgantown, West Virginia. Our business strategy is to leverage cash flow generated from existing assets to maintain relatively stable GOM shelf oil production, profitably grow gas reserves and production in price-advantaged basins such as Appalachia and the Gulf Coast Basin, and profitably grow oil reserves and production in material impact areas such as the deep water GOM and onshore oil. For additional information, contact Kenneth H. Beer, Chief Financial Officer, at 337-521-2210 phone, 337-521-2072 fax or via e-mail at CFO@StoneEnergy.com.

STONE ENERGY CORPORATION

SUMMARY STATISTICS

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STONE ENERGY CORPORATION

CONSOLIDATED STATEMENT OF OPERATIONS

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RECONCILIATION OF NON-GAAP FINANCIAL MEASURE

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CONSOLIDATED BALANCE SHEET

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