The governor of Oklahoma is the head of government of the U.S. state of Oklahoma. Under the Oklahoma Constitution, the governor serves as the head of the Oklahoma executive branch, of the government of Oklahoma. The governor is the ex officio commander-in-chief of the Oklahoma National Guard when not called into federal use. Despite being an executive branch official, the governor also holds legislative and judicial powers. The governor's responsibilities include making yearly "State of the State" addresses to the Oklahoma Legislature, submitting the annual state budget, ensuring that state laws are enforced, and that the peace is preserved. The governor's term is four years in length.

The office was created in 1907 when Oklahoma was officially admitted to the federal Union of the United States as the 46th state, by act of the Congress of the United States and approval by the President. Prior to statehood, the western part of the future state was organized as Oklahoma Territory (1890-1907). In Oklahoma Territory, the chief executive, the predecessor to the elected state governors, was a territorial governor with similar powers who was, like other territorial governors, appointed by the President and confirmed by the United States Senate.

From 1834 to 1907, in the eastern portion of modern Oklahoma state, was the unorganized former Indian Territory, which originally encompassed a much larger tract of unassigned public lands west of the Mississippi River to the Rocky Mountains, reserved for various Native Americans / Indian tribes and nations, removed and transported from the Southeastern United States in the 1830s during the infamous "Trail of Tears". A federal judge of the United States District Court for the Western District of Arkansas, centered in the border town of Fort Smith, exercised judicial powers and sent individual and posses of U.S. Marshals and deputy Marshals to patrol that Territory in lieu of an appointed territorial Governor or other local law enforcement, governing structure or organized territorial government such as the several other federal territories in the Western United States (and later further away of territories of Alaska and Hawaii overseas), during the 19th and early 20th centuries, except for various Indian tribal police on the designated reservations.

Kevin Stitt is the 28th and current governor since 2019. He is a member of the Republican Party. Stitt was first elected in the 2018 Oklahoma gubernatorial election and was reelected in 2022. His second term will expire on January 11, 2027, and he is prohibited from seeking a third term.

Before statehood in 1907, modern day-Oklahoma was composed of the Oklahoma Territory (in the West since 1890) and the Indian Territory in the original far wider / greater expanse of the old Louisiana Purchase of 1803, including today's Midwestern and Western United States. Over subsequent decades through various treaties and outright land grabs, that expanse was later reduced gradually to the eastern half of the modern state from 1834 to 1907. While Indian Territory was semi-independent of the federal government and it's military in far-off Washington, D.C. as Indian nations land, the Oklahoma Territory with its capital city at Guthrie, was an organized federal territory under the supervision of the President, with his executive departmental secretaries in his presidential cabinet, and both houses of the United States Congress (sending a territorial delegate to sit and speak (but no vote) on the floor of the lower chamber of the U.S. House of Representatives at the United States Capitol in Washington. Within the Oklahoma Territory, a traditional American democratic political system was created with Separation of powers and tripartite government existed just like the other states and federal government, including a territorial legislature, a territorial supreme court, and a territorial governor.

The incumbent president of the United States appointed territorial governors and assisting secretary to four-year terms, with "the advice and consent" of the United States Senate. Despite a set term, the governor served at the pleasure of the sitting American president, meaning that the president or his successor could replace him before his term was up.

The governor was the head of the territorial government. He had the power to veto legislation proposed by the territorial legislature and the power to appoint members to his cabinet of executive departments or bureaus, who in turn had to be ratified by territorial assembly lawmakers. The governor had the power to appoint justices to the territorial high court and any lower court judges. The governor was responsible to the president on addressing issues in the federal territory and served as the representative as the federal government of the United States in Washington. He was also the commander-in-chief of any organized the territorial militia.

George Washington Steele (1839–1922, served 1890–1891), served as the first governor of the Oklahoma Territory, appointed by 23rd President Benjamin Harrison (1833–1901, served 1889–1893), a Republican). He vetoed the territorial legislature's attempts to move the state capital from Guthrie to Oklahoma City or Kingfisher. He was instrumental in the establishment of two territorial (later state) universities that would eventually become the University of Oklahoma and the Oklahoma State University (at Stillwater). After only seventeen months in office, Governor Steele resigned effective October 18, 1891. In his place, President Benjamin Harrison then appointed Abraham Jefferson Seay (1832–1915, served 1892–1893), to the governorship as the second occupant. Robert Martin (1833–1897, served 1890–1893), then serving as the secretary of Oklahoma Territory, served briefly himself as acting governor in the four months interim from October 18, 1891, until February 1892, when Governor-designate Seay arrived and took the oath of office in Guthrie.