Kosmos Energy is an American international oil company founded and based in Dallas, Texas. It is incorporated in Bermuda and has offices in Ghana, Mauritania, Senegal and Suriname. The company holds production and development operations offshore Ghana, in addition to discoveries and further exploration operations offshore Mauritania and Senegal, and exploration licenses offshore Sao Tome and Principe, Morocco and Western Sahara. It discovered the Jubilee oil field off the coast of Ghana. Kosmos was the focus of a documentary Big Men that followed the company as it worked to establish the Jubilee oil field in Ghana.

Kosmos Energy was established in 2003 by founding partners James C. Musselman, Brian F. Maxted, W. Greg Dunlevy, and Paul Dailly. Initial backing came from American private equity firms Warburg Pincus and The Blackstone Group.

Kosmos made one of the world's largest recent oil discoveries in June 2007, off the coast of Ghana. The company discovered the Jubilee Oil Field about 60 kilometres (37 mi) offshore. The first oil from the field was produced in 2010. The company and its operations in Ghana, around the time of the Jubilee discovery and work to develop the field, was the focus of Rachel Boynton's 2013 documentary-film Big Men. The documentary was shortened and adapted into a BBC television documentary Storyville: Power, Money, Greed and Oil.

Kosmos went public under the ticker symbol KOS on the New York Stock Exchange on May 10, 2011. The initial public offering raised more than anticipated, selling 33 million shares at $18 each. It was listed on the London Stock Exchange on August 21, 2017.

Kosmos and Chevron reached a deal in June 2012, where subsidiary Chevron Global Energy Inc. received a 50% working interest in Block 45 and Block 42 in Suriname, to boost operations. In May 2016, Kosmos reached a farm-out agreement with a subsidiary of Hess Corp., wherein Hess acquired a 33% non-operated interest in Block 42 from Kosmos and Chevron.

Kosmos began a controversial oil drilling project in the Cap Boujdour area in 2014 off the coast of disputed territory of Western Sahara. In an article from February 2015, former UN legal counsel Hans Corell stated that the ongoing exploration activities by Kosmos and Glencore is in violation of the legal opinion he wrote for the UN Security Council. Kosmos has responded that its operations comply with international law and fall in line with the UN opinion. Kosmos officials also told media it recognized that its work in the area must occur alongside UN-led mediation.

The company said local populations in Western Sahara would benefit from the economic development of the region. A Kosmos official told Reuters, "If we are successful, we believe responsible resource development has the potential to create significant social and economic benefits for Western Sahara and its people. We have worked in close partnership with Morocco — as the de facto administering power of the territory. They have a vital role to play in ensuring benefit sharing, among other important issues, will happen should we be successful".

In 2016, Norway's Council on Ethics recommended that the country's Government Pension Fund Global exclude Kosmos Energy and Cairn Energy Plc. from its investment portfolio due to their activities in Western Sahara. In June 2016, the Financial Times quoted Kosmos correspondence with the Council on Ethics: "We fundamentally disagree with the council's assessment of our activities offshore Western Sahara, where we have spent considerable time on the ground working with local people to understand their views of oil and gas exploration. The council's decision fails to recognize that people in Western Sahara—whom we have met in hundreds of face-to-face conversations—want the economic opportunities that come from increased foreign investment."

Kosmos made two significant gas discoveries offshore Mauritania in 2015. Kosmos discovered gas at its Tortue-1 exploration well in Block C-8 in April 2015, followed by another gas discovery in its Marsouin-1 exploration well in the northern part of Block C-8. A few kilometers south of Tortue-1, Kosmos Energy discovered gas at its Guembeul-1 exploration well offshore Senegal in January 2016.

The company continued to make gas discoveries in 2016 and 2017, including significant natural gas resources at the Teranga-1 exploration well offshore Senegal in 2016. In December 2016, Kosmos and BP entered a partnership in Mauritania and Senegal. BP acquired a 62% working interest, including operatorship, of Kosmos' exploration blocks in Mauritania and a 32.49% effective working interest in Kosmos' Senegal exploration blocks. In May 2017, the two companies made a major discovery off the coast of Senegal while drilling the Yakaar-1 exploration well.

Kosmos Energy discovered the Jubilee Oil Field in 2007. It owns a 24.1% stake in Jubilee Oil Field. The field is estimated to hold up to 1 billion barrels (160 million cubic metres) of oil and 800 billion cubic feet (23 billion cubic metres) of natural gas. As of May 2017, the Jubilee field produces about 100,000 barrels per day (16,000 cubic metres per day) of oil. United States Secretary of State Hillary Clinton reportedly advocated for Kosmos and other U.S.-based oil companies in Ghana as Kosmos began development of the Jubilee field.

In addition to Jubilee, Kosmos is a partner on the TEN (Tweneboa, Enyenra and Ntomme) project developing the Tweneboa, Enyenra, and Ntomme hydrocarbon accumulations. Kosmos holds a 17% stake in the TEN, which sits approximately 30 miles (48 km) offshore Ghana. Oil first flowed from TEN in 2016.

Kosmos operates in the Cayar and St. Louis blocks offshore Senegal. It holds a 32.51% interest in each of its two exploration licenses.

Kosmos and BP have a farm-out agreement over the joint gas discovery in Mauritania and Senegal, as well as future exploration. Under the deal, Kosmos focuses on exploration, while BP controls development and production operations. The two companies have discovered an estimated 15 trillion cubic feet (420 billion cubic metres) of gross Pmean gas resource at the Yakaar-1 exploration well.

In Mauritania, Kosmos holds 28% stakes in four blocks. It made a significant gas discovery at its Tortue-1 well in Block C-8, offshore Mauritania, in April 2015. The well was drilled to test the Tortue West prospect, forming a part of the Greater Tortue complex. Its next discovery offshore came at Kosmos' Marsouin-1 exploration well in the northern part of Block C-8. With results from its Ahmeyim-2 appraisal well, Kosmos estimated the Tortue West contains 15 trillion cubic feet (420 billion cubic metres) of gas, and the Greater Tortue Complex contains more than 20 trillion cubic feet (570 billion cubic metres). Company officials said this discovery confirmed that the Tortue gas resource, which is also called Ahmeyim, straddles the maritime boundary between Senegal and Mauritania.

In Suriname, Kosmos operates in two exploration license areas. It holds a 50% interest in Block 45 and a 33% interest in Block 42.

Kosmos has ownership interests in four blocks offshore Sao Tome and Principe: 5, 6, 11, and 12. It operates blocks 5, 11, and 12; Galp operates block 6.

With Galp, Kosmos ordered a 3D seismic survey of a large stretch of ocean floor. According to The Wall Street Journal, the survey was "one of the biggest offshore oil exploration efforts of its kind in the region". The survey was completed on August 20, 2017.

As operator, Kosmos holds a 55% interest of the Boujdour Maritime block and 75% interest of the Essaouira block. In October 2013, Kosmos reached a farm-out deal with Cairn Energy subsidiary Capricorn Exploration & Development Company Ltd. Under the deal, Cairn took a 20% non-operated interest in Boujdour Maritime block.

The license of the Boujdour block is signed with the Moroccan state oil company ONHYM.

Kosmos announced in May 2014 it would plug and abandon its FA-1 well in the Foum Assaka Offshore block. While it did not find oil, the company said there was evidence of a working petroleum system and the well provided important seismic calibration details. These details were incorporated into the company's petroleum system analysis.

On March 2, 2015, Kosmos Energy said its CB-1 exploration well in Cap Boujdour made a small discovery. The discovery was noncommercial, and the well was plugged and abandoned.

In October 2017, Kosmos signed three production-sharing contracts with Equatorial Guinea for the EG-21, S, and W offshore blocks. Under the contract, Kosmos will hold an 80% stake in each block, while a national oil company GEPetrol will hold the remaining stake.

Kosmos Energy is headquartered in Dallas, Texas, and incorporated in Bermuda. It trades on the New York and London stock exchanges under the ticker symbol KOS and employs about 275 workers globally.

The company is governed by a 10-member board of directors. Its executive leadership includes chairman and CEO Andrew G. Inglis, Chief Exploration Officer Brian F. Maxted, and Senior Vice President and Chief Financial Officer Thomas P. Chambers.

In Dallas, Kosmos gave $450,000 to the Perot Museum of Nature and Science, creating the Kosmos Energy STEM Teacher Institute Kosmos also supports the Dallas Museum of Art. It is the presenting sponsor of the Keir Collection of Islamic Art.

In Ghana, the company established the Kosmos Innovation Center in 2016, offering programs to help diversify Ghana's economy, including agriculture industry specifically. In addition, Kosmos has worked with the Safe Water Network to provide residents in Western Ghana with access to clean water.

The company has partnered with an NGO, Le Partenariat, to sponsor programs in Senegal to improve the environment.

Kosmos donated $67,500 worth of equipment to Polytechnic College of Suriname in 2016, to be used in its undergraduate Mechanical Engineering and Infrastructure programs. In 2017, the company donated $56,600 worth of equipment for students studying mineral production at Anton de Kom University of Suriname. Kosmos has worked with international security company Safe Start to develop and deliver a safety training program for technical schools in the country.