Exhibit 99.1

Press Release

Gulfport Energy Corporation Reports Second Quarter 2017 Results

OKLAHOMA CITY (August 8, 2017) Gulfport Energy Corporation (NASDAQ: GPOR) (“Gulfport” or the “Company”) today reported financial and operational results for the quarter ended June 30, 2017 and provided an update on its 2017 activities. Key information for the second quarter of 2017 includes the following:

Second Quarter Financial Results

For the second quarter of 2017, Gulfport reported net income of $105.9 million, or $0.58 per diluted share, on revenues of $324.0 million. For the second quarter of 2017, EBITDA (as defined and reconciled below for each period presented) was $212.8 million and cash flow from operating activities before changes in operating assets and liabilities (as defined and reconciled below for each period presented) was $145.0 million. Gulfport’s GAAP net income for the second quarter of 2017 includes the following items:

Excluding the effect of these items, Gulfport’s financial results for the second quarter of 2017 would have been as follows:

Year-To-Date 2017 Financial Results

For the six-month period ended June 30, 2017, Gulfport reported net income of $260.4 million, or $1.47 per diluted share, on revenues of $657.0 million. For the six-month period ended June 30, 2017, EBITDA was $457.0 million and cash flow from operating activities before changes in operating assets and liabilities was $266.7 million. Gulfport’s GAAP net income for the six-month period ended June 30, 2017 includes the following items:

Excluding the effect of these items, Gulfport’s financial results for the six-month period ended June 30, 2017 would have been as follows:

Production and Realized Prices

Gulfport’s net daily production for the second quarter of 2017 averaged approximately 1,038.4 MMcfe per day. For the second quarter of 2017, Gulfport’s net daily production mix was comprised of approximately 88% natural gas, 8% natural gas liquids (“NGL”) and 4% oil.

Gulfport’s realized prices for the second quarter of 2017 were $3.16 per Mcf of natural gas, $57.86 per barrel of oil and $0.45 per gallon of NGL, resulting in a total equivalent price of $3.43 per Mcfe. Gulfport’s realized prices for the second quarter of 2017 include an aggregate

non-cash derivative gain of $59.9 million. Before the impact of derivatives, realized prices for the second quarter of 2017, including transportation costs, were $2.48 per Mcf of natural gas, $45.33 per barrel of oil and $0.45 per gallon of NGL, for a total equivalent price of $2.74 per Mcfe.

GULFPORT ENERGY CORPORATION

PRODUCTION SCHEDULE

(Unaudited)

The table below summarizes Gulfport’s second quarter of 2017 production by asset area:

GULFPORT ENERGY CORPORATION

PRODUCTION BY AREA

(Unaudited)

Operational Update

The table below summarizes Gulfport’s activity for the six-month period ended June 30, 2017 and the number of net wells expected to be drilled and turned-to-sales for the remainder of 2017:

GULFPORT ENERGY CORPORATION

ACTIVITY SUMMARY

(Unaudited)

Utica Shale

In the Utica Shale, during the second quarter of 2017, Gulfport spud 28 gross (25.7 net) operated wells. The wells drilled during the second quarter of 2017 had an average lateral length of approximately 8,408 feet, an increase of 3% over the first quarter of 2017. Normalizing to an 8,000 foot lateral length, Gulfport’s average drilling days during the second quarter of 2017 from spud to rig release totaled approximately 18.0 days. In addition, Gulfport turned-to-sales 29 gross (26.7 net) operated wells with an average lateral length of approximately 7,802 feet. For the six-month period ended June 30, 2017, Gulfport’s well costs averaged approximately $1,094 per foot of lateral in the Utica Shale.

The table below summarizes notable recent well results across Gulfport’s acreage position:

GULFPORT ENERGY CORPORATION

NOTABLE WELL RESULTS SUMMARY

(Unaudited)

Note: Data provided is three-stream production data.

During the second quarter of 2017, net production from Gulfport’s Utica acreage averaged approximately 857.2 MMcfe per day, an increase of 14% over the first quarter of 2017 and an increase of 33% over the second quarter of 2016.

During the six-month period ended June 30, 2017, Gulfport acquired approximately 5,500 net acres within its core dry gas operating area. In addition, the Company completed an acquisition of mineral interests, increasing its net revenue interest (NRI) on over 5,000 acres by approximately 8%. Gulfport holds approximately 211,000 net acres under lease today in the Utica Shale.

At present, Gulfport has six operated horizontal drilling rigs active in the play.

SCOOP

In the SCOOP, during the second quarter of 2017, Gulfport spud three gross (2.4 net) operated Woodford wells. The wells drilled during the second quarter of 2017 had an average lateral length of 8,804 feet, an increase of 12% over the first quarter of 2017. Normalizing to a 7,500 foot lateral length, Gulfport’s average drilling days during the second quarter of 2017 from spud to rig release totaled approximately 64.8 days.

During the second quarter of 2017, net production from the acreage averaged approximately 162.0 MMcfe per day.

During the six-month period ended June 30, 2017, Gulfport acquired approximately 2,600 net acres within its core operating area, bringing the Company’s holdings to a total of approximately 49,200 net surface acres under lease today in the SCOOP.

At present, Gulfport temporarily has six operated horizontal drilling rigs active in the play. The Company is in the process of high-grading its rig equipment and expects to return to four horizontal rigs in the coming weeks as contracts expire. Subsequent to the second quarter of 2017, Gulfport spud both a Springer and Sycamore well in the SCOOP.

As previously announced, during the second quarter of 2017 Gulfport turned-to-sales two gross (1.2 net) Woodford wells, the Vinson 2-22X27H and Vinson 3R-22X27H, located in the wet gas window in southern Grady County. Following 60 days of production, the Vinson 2-22X27H has cumulatively produced 769.6 MMcf of natural gas and 2,138 barrels of oil and the Vinson 3R-22X27H has cumulatively produced 927.5 MMcf of natural gas and 2,468 barrels of oil. Based upon the composition analysis, the gas being produced from the Vinson pad is 1,118 BTU gas and yielding 35.7 barrels of NGLs per MMcf of natural gas and results in a natural gas shrink of 11%. On a three-stream basis, the Vinson 2-22X27H produced at an average 60-day peak rate of 14.4 MMcfe per day, which is comprised of approximately 79% natural gas, 19% natural gas liquids and 2% oil. The Vinson 3R-22X27H produced at an average 60-day peak rate of 17.3 MMcfe per day, which is comprised of approximately 79% natural gas, 19% natural gas liquids and 2% oil. In addition to these results, Gulfport recently began flowback on two gross operated Woodford wells and is in various stages of completion on an incremental five gross operated Woodford wells.

Southern Louisiana

At its West Cote Blanche Bay and Hackberry fields, during the second quarter of 2017, Gulfport spud six wells and performed 29 recompletions at the fields. Net production during the second quarter of 2017 totaled approximately 18.1 MMcfe per day.

2017 Capital Budget and Production Guidance Update

For the six-month period ended June 30, 2017, Gulfport’s drilling and completion capital expenditures totaled $536.1 million, midstream capital expenditures totaled $23.0 million and leasehold capital expenditures totaled $55.2 million. Michael Moore, Gulfport’s Chief Executive Officer and President commented, “As planned, the second quarter of 2017 marks our most active quarter from both an activity and capital spending standpoint for 2017. We currently forecast a similar to slightly lower drilling and completion spend during the third quarter of 2017, decreasing significantly in the fourth quarter of 2017 and reaffirm our capital budget for 2017 of approximately $1.0 to $1.1 billion.”

As previously announced, based on actual results during the six-month period ended June 30, 2017, Gulfport increases its 2017 production guidance and currently forecasts that 2017 average daily net production will be in the range of 1,065 MMcfe to 1,100 MMcfe per day, an increase of 48% to 53% over its 2016 average daily net production of 719.8 MMcfe per day.

In addition, as previously announced, based on actual results during the six-month period ended June 30, 2017 and utilizing current strip pricing at the various regional pricing points at which the Company sells its natural gas, Gulfport now forecasts its realized natural gas price, before the effect of hedges and inclusive of the Company’s firm transportation expense, will average in the range of $0.62 to $0.68 per Mcf below NYMEX settlement prices in 2017. Gulfport reiterated its expected realized NGL price and realized oil price and expects that its 2017 realized NGL price, before the effect of hedges and including transportation expense, will be approximately 45% of WTI and its 2017 realized oil price will be in the range of $3.75 to $4.75 per barrel below WTI.

The table below summarizes the Company’s full year 2017 guidance:

GULFPORT ENERGY CORPORATION

COMPANY GUIDANCE

2017 Financial Position and Liquidity

As of June 30, 2017, Gulfport had cash on hand of approximately $117.6 million. As of June 30, 2017, $210.0 million was outstanding under Gulfport’s revolving credit facility with outstanding letters of credit totaling $237.5 million.

Derivatives

Gulfport has hedged a portion of its expected production to lock in prices and returns that provide certainty of cash flow to execute on its capital plans. Since May 8, 2017, the Company has added approximately 75 BBtupd of natural gas fixed price swaps for the remainder of 2017, 166 BBtupd of natural gas fixed price swaps for 2018 and 37 BBtupd of natural gas fixed price swaps for 2019.

The table below sets forth the Company’s hedging positions as of August 8, 2017.

GULFPORT ENERGY CORPORATION

COMMODITY DERIVATIVES - HEDGE POSITION

(Unaudited)

Presentation

An updated presentation has been posted to the Company’s website. The presentation can be found at www.gulfportenergy.com under the “Company Information” 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 Wednesday, August 9, 2017 at 8:00 a.m. CDT to discuss its second quarter of 2017 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. 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 is an independent natural gas and oil company focused on the exploration and development of natural gas and oil properties in North America and is one of the largest producers of natural gas in the contiguous United States. Headquartered in Oklahoma City, Gulfport holds significant acreage positions in the Utica Shale of Eastern Ohio and the SCOOP Woodford and SCOOP Springer plays in Oklahoma. In addition, Gulfport holds an acreage position along the Louisiana Gulf Coast, a position in the Alberta Oil Sands in Canada through its approximately 25% interest in Grizzly Oil Sands ULC and has an approximately 25% equity interest in Mammoth Energy Services, Inc. (NASDAQ: TUSK). For more information, please visit www.gulfportenergy.com.

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 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 (including the properties recently acquired

from Vitruvian II Woodford, LLC) 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 (loss), 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 non-cash derivative (gain) loss, acquisition expense and (income) 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 income is a non-GAAP financial measure equal to pre-tax net loss less non-cash derivative (gain) loss, acquisition expense and (income) loss from equity method 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 income 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 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 income 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 income 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:

Jessica Wills – Manager, Investor Relations and Research

jwills@gulfportenergy.com

405-252-4550

GULFPORT ENERGY CORPORATION

CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited)

GULFPORT ENERGY CORPORATION

CONSOLIDATED BALANCE SHEETS

(Unaudited)

GULFPORT ENERGY CORPORATION

RECONCILIATION OF EBITDA AND CASH FLOW

(Unaudited)

GULFPORT ENERGY CORPORATION

RECONCILIATION OF ADJUSTED EBITDA

(Unaudited)

GULFPORT ENERGY CORPORATION

RECONCILIATION OF ADJUSTED NET INCOME

(Unaudited)