Governor

A governor is a political leader. Several colony worlds are run by governors.

Robert Chen was governor of the State of California in 2024. (DS9: "Past Tense, Part II")

Kor was briefly the Klingon military governor of Organia during the First Federation-Klingon War in 2267. (TOS: "Errand of Mercy")

Donald Cory was governor of the penal colony on Elba II in 2268. (TOS: "Whom Gods Destroy")

Robert Wesley was governor of Mantilles in 2270. (TAS: "One of Our Planets is Missing")

Karnas was the governor of Mordan IV in 2364. (TNG: "Too Short a Season")

Vagh was the Klingon governor of Krios in 2368. (TNG: "The Mind's Eye")

Torak was the Klingon governor in charge of Sector 2520 in 2369. (TNG: "Aquiel")

Maturin was the governor of the Caldos colony in 2370. (TNG: "Sub Rosa")

Avesta was the governor of the Bajoran colony Prophet's Landing in 2371. (DS9: "Heart of Stone")

In an alternate timeline, Worf was governor of H'atoria in 2395. (TNG: "All Good Things...")

Apocrypha

Klingon Admiral Vlict Kenka was governor of Hrakhour, a planet of the edge of Klingon space. He ended the generations-long control his family had over the planet when he massacred the entire population in 2268 in response to the beginnings of a pacifist movement. (Star Trek: 25th Anniversary (PC): Episode 5: "The Feathered Serpent")

Rajat Kallarax was Klingon governor of Sagrad, a planet deep within the empire, at this same time. (Star Trek: 25th Anniversary (PC): Episode 5: "The Feathered Serpent")