Speaking at a news conference, Qatar's Energy Minister Saad al-Kaabi said the country would withdraw from OPEC on January 1, 2019, ending a membership which has stood for more than half-a-century.
The decision comes after Qatar reviewed ways in which it could improve its global standing and plan its long-term strategy.
While Qatar is one of OPEC's smallest oil producers, especially when compared to the likes of de facto leader Saudi Arabia, it is one of the world's largest producers of liquefied natural gas (LNG).
The country's energy minister said Monday that the move represents a "technical and strategic" change, Reuters reported, and was not politically motivated.
Qatar's Al-Kaabi also said the decision was not linked to the 18-month political and economic boycott of Doha.
Since June 2017, OPEC kingpin Saudi Arabia — along with three other Arab states — has cut trade and transport ties with Qatar, accusing the country of supporting terrorism and their regional rival, Iran. Qatar denies the claims, saying the boycott hampers its national sovereignty.
The Middle East-dominated group's final meeting of the calendar year is now expected to be Qatar's last. It has been an official OPEC member since 1961.