Exhibit 99.1

Press Release

Gulfport Energy Corporation Reports Third Quarter 2015 Results

OKLAHOMA CITY (November 4, 2015) Gulfport Energy Corporation (NASDAQ: GPOR) (“Gulfport” or the “Company”) today reported financial and operational results for the quarter ended September 30, 2015 and provided an update on its 2015 activities. Key information for the third quarter includes the following:

Michael G. Moore, Chief Executive Officer, commented, “While we are certainly proud of our operational performance this quarter, we also acknowledge these are challenging times for the industry. Gulfport has differentiated itself to not only weather these challenges but navigate them opportunistically and ultimately exit in a position of strength. Our core philosophy of maintaining conservative leverage and preserving the strength of our balance sheet has been and will continue to be the driving force of our business and our number one priority.”

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“With regard to 2016, Gulfport anticipates providing its 2016 guidance and budgeted activity levels in early 2016. In light of today’s commodity price environment, we currently plan to forego adding a fifth rig in the Utica at the beginning of 2016, idling a completion crew during the first quarter of 2016 and we are directionally moving downward towards the middle of the previously provided bookends of activity next year. As we contemplate levels of activity going forward, I assure you that we will continue to act thoughtfully and in a financially responsible manner.”

Financial Results

For the third quarter of 2015, Gulfport reported a net loss of $388.2 million, or $3.59 per diluted share, on oil and natural gas revenues of $230.4 million. For the third quarter of 2015, EBITDA (as defined below) was $94.6 million and cash flow from operating activities before changes in working capital was $82.8 million. The GAAP net income for the third quarter of 2015 included the following items:

Excluding the effect of these items, Gulfport’s financial results for the third quarter of 2015 were as follows:

Production and Realized Prices

Gulfport’s net daily production for the third quarter of 2015 averaged approximately 647.1 MMcfe per day. For the third quarter of 2015, Gulfport’s net daily production mix was comprised of approximately 81% natural gas, 12% natural gas liquids and 7% oil. Subsequent to the third quarter of 2015, estimated October 2015 net production averaged approximately 706.3 MMcfe per day.

Gulfport’s realized prices for the third quarter of 2015 were $3.72 per Mcf of natural gas, $0.19 per gallon of NGL and $57.02 per barrel of oil, resulting in a total equivalent price of $3.87 per Mcfe. Gulfport’s realized prices for the third quarter of 2015 include an aggregate non-cash unrealized hedge gain of $62.2 million. Before the impact of derivatives, realized prices for the third quarter of 2015, including transportation costs, were $2.07 per Mcf of natural gas, $0.19 per gallon of NGL and $40.53 per barrel of oil, for a total equivalent price of $2.33 per Mcfe.

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GULFPORT ENERGY CORPORATION

PRODUCTION SCHEDULE

(Unaudited)

Temporary Voluntary Production Curtailment

Strong results from Gulfport’s existing production base and efficiencies realized in its completion activities have resulted in Gulfport’s production trending ahead of expectations. As a result of weakness in natural gas commodity pricing, Gulfport has made the decision to temporarily and voluntarily curtail approximately 100 MMcfe per day of production beginning November 1, 2015 through early 2016. Despite this curtailment, Gulfport reiterates its 2015 production guidance of 517 to 541 MMcfe per day.

As a result of production exceeding expectations during the third quarter of 2015, Gulfport experienced a wider-than-expected basis differential for the quarter. Gulfport’s realized natural gas price before the impact of derivatives and including transportation costs was $2.07 per Mcf, equating to a $0.70 per Mcf basis differential to NYMEX during the quarter. Gulfport expects this basis differential will narrow during the fourth quarter as a result of the previously mentioned temporary voluntary curtailments and due to increased seasonal demand during the winter. Reflecting these factors, Gulfport now expects its natural gas pricing to average in the range of $0.68 to $0.72 per MMBtu below NYMEX during 2015.

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Firm Transportation & Commitments Update

Gulfport is committed to securing additional firm arrangements to further support its realizations. Accordingly, Gulfport has entered into an additional 120,000 MMBtu per day of firm arrangements with multiple counterparties beginning in February 2016 to flow out of the Appalachian Basin into the premium Midwest markets, securing additional pricing certainty for incremental volumes in the upcoming year.

Derivatives

Gulfport continues to hedge a significant portion of its expected production to lock in prices and returns that provide certainty of cash flow to execute on its capital plans. The table below sets forth the Company’s hedging positions as of November 4, 2015.

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GULFPORT ENERGY CORPORATION

COMMODITY DERIVATIVES—HEDGE POSITION AS OF NOVEMBER 3, 2015

(Unaudited)

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2015 Capital Spending

During the third quarter of 2015, Gulfport’s capital expenditures totaled approximately $140 million. Throughout 2015, Gulfport has been focused on driving efficiencies and, as a result, has realized significantly increased productivity on completion activities. To capitalize on these efficiencies, Gulfport accelerated its completion pace ahead of the winter and now expects to complete approximately 10 additional net wells during 2015. While this additional activity will increase Gulfport’s spending by approximately $60 million during 2015, it is expected to be offset by Gulfport’s plans to halt all completion operations during the first quarter of 2016.

Financial Position and Liquidity

As of September 30, 2015, Gulfport had cash on hand of approximately $228.1 million. In addition, during September 2015, Gulfport’s lenders completed their fall redetermination under the Company’s revolving credit facility, and increased Gulfport’s borrowing base from $575 million to $700 million. As of September 30, 2015, Gulfport’s revolving credit facility was undrawn with outstanding letters of credit totaling $177.1 million.

2015 Capital Budget and Guidance

As a result of increased efficiencies, Gulfport has undertaken additional activity in the Utica Shale and currently expects its exploration and production capital expenditures will total approximately $667 million to $677 million in 2015. Additionally, excluding the recently completed Paloma and AEU acquisitions, Gulfport reiterates its expectation to spend approximately $85 million to $95 million on leasehold acquisitions in the Utica Shale during 2015.

Despite voluntary curtailments, Gulfport reiterates its 2015 production guidance and forecasts its 2015 average daily production to be in the range of 517 MMcfe per day to 541 MMcfe per day. In addition, production is forecasted to be 75% to 85% natural gas.

Gulfport currently expects its realized natural gas price, before the effect of hedges and inclusive of the Company’s firm transportation expense, to average in the range of $0.68 to $0.72 per MMBtu below NYMEX settlement prices in 2015. In addition, Gulfport currently forecasts its 2015 realized oil price will be approximately $7.00 per barrel below WTI and its 2015 realized NGL price will be in the range of $0.32 to $0.37 per gallon.

Gulfport continues to realize economies of scale as it develops its Utica Shale assets and, as a result, its per unit operating costs have trended lower.

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The table below summarizes the Company’s full-year 2015 guidance:

GULFPORT ENERGY CORPORATION

COMPANY GUIDANCE

Operational Results

Utica Shale Activities Update

In the Utica Shale, Gulfport spud 15 gross (12.6 net) wells and turned-to-sales 16 gross (15.4 net) wells during the third quarter of 2015. During the third quarter, net production from Gulfport’s Utica acreage averaged approximately 624.5 MMcfe per day. Due to increased efficiencies and further reductions in service costs, Gulfport has realized a 5% to 8% decrease in total expected well costs relative to the estimates provided in August 2015. At present, Gulfport has four operated horizontal rigs drilling in the play.

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Southern Louisiana Activities Update

At its West Cote Blanche Bay and Hackberry fields, during the third quarter of 2015 Gulfport performed 25 recompletions. During the third quarter, net production at these fields totaled approximately 3,559 barrels of oil equivalent per day.

Presentation

An updated presentation has been posted to the Company’s website. The presentation can be found at www.gulfportenergy.com under the “Webcasts & Presentations” section on the “Investor Relations” page. Information on the Company’s website does not constitute a portion of this press release.

Conference Call

Gulfport will hold a conference call on Thursday, November 5, 2015 at 8:00 a.m. CST to discuss its third quarter of 2015 financial and operational results and to provide an update on the Company’s recent activities.

Interested parties may listen to the call via Gulfport’s website at www.gulfportenergy.com or by calling toll-free at 866-373-3408 or 412-902-1039 for international callers. The passcode for the call is 13622396. A replay of the call will be available for two weeks at 877-660-6853 or 201-612-7415 for international callers. The replay passcode is 13622396. The webcast will also be available for two weeks on the Company’s website and can be accessed on the Company’s “Investor Relations” page.

About Gulfport

Gulfport Energy Corporation is an Oklahoma City-based independent oil and natural gas exploration and production company with its principal producing properties located in the Utica Shale of Eastern Ohio and along the Louisiana Gulf Coast. In addition, Gulfport holds a sizeable acreage position in the Alberta Oil Sands in Canada through its 25% interest in Grizzly Oil Sands ULC.

Forward Looking Statements

This press release includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements, other than statements of historical facts, included in this press release that address activities, events or developments that Gulfport expects or anticipates will or may occur in the future, future capital expenditures (including the amount and nature thereof), business strategy and measures to implement strategy, competitive strength, goals, expansion and growth of Gulfport’s business and operations, plans, market conditions, references to future success, reference to intentions as to future matters and other such matters are forward-looking statements. These statements are based on certain assumptions and analyses made by Gulfport in light of its experience and its perception

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of historical trends, current conditions and expected future developments as well as other factors it believes are appropriate in the circumstances. However, whether actual results and developments will conform with Gulfport’s expectations and predictions is subject to a number of risks and uncertainties, general economic, market, credit or business conditions; the opportunities (or lack thereof) that may be presented to and pursued by Gulfport; Gulfport’s ability to identify, complete and integrate acquisitions of properties and businesses; competitive actions by other oil and gas companies; changes in laws or regulations; and other factors, many of which are beyond the control of Gulfport. Information concerning these and other factors can be found in the Company’s filings with the Securities and Exchange Commission, including its Forms 10-K, 10-Q and 8-K. Consequently, all of the forward-looking statements made in this news release are qualified by these cautionary statements and there can be no assurances that the actual results or developments anticipated by Gulfport will be realized, or even if realized, that they will have the expected consequences to or effects on Gulfport, its business or operations. Gulfport has no intention, and disclaims any obligation, to update or revise any forward-looking statements, whether as a result of new information, future results or otherwise.

Non-GAAP Financial Measures

EBITDA is a non-GAAP financial measure equal to net income, the most directly comparable GAAP financial measure, plus interest expense, income tax (benefit) expense, accretion expense, depreciation, depletion and amortization and impairment of oil and gas properties. Adjusted EBITDA is a non-GAAP financial measure equal to EBITDA less unrealized gain/loss from hedges, loss from impairment of Grizzly equity investment and gain/loss from equity method investments. Cash flow from operating activities before changes in operating assets and liabilities is a non-GAAP financial measure equal to cash provided by operating activity before changes in operating assets and liabilities. Adjusted net loss is a non-GAAP financial measure equal to pre-tax net income less unrealized gain/loss from hedges, loss from impairment of oil and gas properties, impairment of Grizzly equity investment and gain/loss from equity investments. The Company has presented EBITDA and adjusted EBITDA because it uses these measures as an integral part of its internal reporting to evaluate its performance and the performance of its senior management. These measures are considered important indicators of the operational strength of the Company’s business and eliminate the uneven effect of considerable amounts of non-cash depletion, depreciation of tangible assets and amortization of certain intangible assets. A limitation of these measures, however, is that they do not reflect the periodic costs of certain capitalized tangible and intangible assets used in generating revenues in the Company’s business. Management evaluates the costs of such tangible and intangible assets and the impact of related impairments through other financial measures, such as capital expenditures, investment spending and return on capital. Therefore, the Company believes that these measures provide useful information to its investors regarding its performance and overall results of operations. EBITDA, adjusted EBITDA, adjusted net loss and cash flow from operating activities before changes in operating assets and liabilities are not intended to be performance measures that should be regarded as an alternative to, or more meaningful than, either net income

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as an indicator of operating performance or to cash flows from operating activities as a measure of liquidity. In addition, EBITDA, adjusted EBITDA, adjusted net loss and cash flow from operating activities before changes in operating assets and liabilities are not intended to represent funds available for dividends, reinvestment or other discretionary uses, and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with GAAP. The EBITDA, adjusted EBITDA, adjusted net loss and cash flow from operating activities before changes in operating assets and liabilities presented in this press release may not be comparable to similarly titled measures presented by other companies, and may not be identical to corresponding measures used in the Company’s various agreements.

Investor & Media Contact:

Paul Heerwagen – Vice President, Corporate Development

pheerwagen@gulfportenergy.com

405-242-4888

Jessica Wills – Manager, Investor Relations and Research

jwills@gulfportenergy.com

405-242-4421

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GULFPORT ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

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GULFPORT ENERGY CORPORATION

CONSOLIDATED BALANCE SHEETS

(Unaudited)

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GULFPORT ENERGY CORPORATION

RECONCILIATION OF EBITDA AND CASH FLOW

(Unaudited)

GULFPORT ENERGY CORPORATION

RECONCILIATION OF ADJUSTED EBITDA

(Unaudited)

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GULFPORT ENERGY CORPORATION

RECONCILIATION OF ADJUSTED NET LOSS

(Unaudited)

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