List of governors of California before 1850

Below is a list of the governors of early California, before its admission as the 31st U.S. state. First explored by Gaspar de Portolá, with colonies established at San Diego and Monterey, Las Californias was a remote, sparsely settled Spanish province of the viceroyalty of New Spain. In 1822, following Mexican independence, California became part of Mexico.
In 1836, a coup led by Californios Juan Bautista Alvarado and José Castro eventually resulted in Alvarado becoming governor. That conflict ended in 1838, when the central government of Mexico recognized Alvarado as California Governor. The territorial diputación approved the appointment.
Another disputed governorship occurred in 1844, settled when another Californio, Pio Pico, became the last Governor of Mexican California. In 1846, the "Bear Flag Revolt" in Sonoma declared California an independent republic—the "Bear Flag Republic". No government was formed, however, and the revolt did not have time to spread very far because California came under U.S. military occupation at the outset of the Mexican–American War less than a month later. California was ceded to the U.S. in 1848, and was admitted as the 31st U.S. state on September 9, 1850. Peter Burnett, the last governor of the post-war military territory, became its first state governor after admission.

Spanish rule (1769–1822)

The Spanish Empire established its rule in the Californias in 1769. During this time, the province of Las Californias encompassed a massive territorial expanse, including both Alta California and Baja California, which were governed under a military administration led by the Governor of Las Californias. In 1804, Las Californias were officially divided into two administrations: Alta California, based in Monterey, and Baja California, based in Loreto.

Spanish governors of Las Californias (1769–1804)

From 1769 to 1804, Las Californias were governed as one administrative unit within the Spanish Empire, the province of Las Californias. Following 1804, Alta California and Baja California each had their own administration.

No.	Portrait	Governor	Took office	Left office	Notes
1st		Gaspar de Portolá	1767	1770	Led the Portolá expedition Founded Monterey
2nd		Felipe de Barri	1770	1774	While Barri officially served as Governor of Las Californias, Fages maintained effective military control over Alta California, taking advantage of Barri's government being based in Baja California.
Acting		Pedro Fages	1770	1774	While Barri officially served as Governor of Las Californias, Fages maintained effective military control over Alta California. Fages effectively stepped down as acting governor in 1774, at the request of Junípero Serra
3rd		Fernando Rivera y Moncada	1774	1777	Founded San Francisco
4th		Felipe de Neve	1777	1782	Founded Los Angeles Founded San Jose
5th		Pedro Fages	1782	1791	Fages previously served as the acting military governor of Alta California from 1770 to 1774, during Barri's tenure, prior to officially serving as Governor of Las Californias
6th		José Antonio Roméu	1791	1792	Roméu died soon after his appointment, prior to officially ending his tenure of office.
Interim		José Joaquín de Arrillaga	1792	1794	Arrillaga was designated as interim governor following the death of Roméu in 1792, until the appointment of Borica in 1794.
7th		Diego de Borica	1794	1800	Founded Branciforte
Interim		Pedro de Alberní y Teixidor	1800	1800	Alberní served as interim governor following Borica's resignation and prior to Arrillaga's appointment.
8th		José Joaquín de Arrillaga	1800	1804	Arrillaga was served as Governor of Las Californias until 1804, when Las Californias were administratively divided into Alta California and Baja California. Arrillaga subsequently served as Governor of Alta California until his death in 1814.

Spanish governors of Alta California (1804–1822)

Following the division of the province of Las Californias in 1804, Alta California came to have its own administration. José Joaquín de Arrillaga, who had served as Governor of Las Californias until 1804 subsequently served as the first governor of Alta California.

No.	Portrait	Governor	Took office	Left office	Notes
1st		José Joaquín de Arrillaga	1804	1814	Arrillaga was served as Governor of Las Californias until 1804, when Las Californias were administratively divided into Alta California and Baja California. Arrillaga subsequently served as Governor of Alta California until his death in 1814.
Interim		José Darío Argüello	1814	1815	Argüello was served as interim governor following the death of Arrillaga and prior to the appointment of Solá.
2nd		Pablo Vicente de Solá	1815	1822	Solá successfully oversaw the transition of Alta California from Spanish rule to newly independent Mexico.

Mexican rule (1822–1846)

Following the Mexican War of Independence from the Spanish, both of the Californias became part of the newly independent Mexico in 1822. Mexican rule was interrupted from 1836 to 1838 by the Californio independence movement led by Juan Bautista Alvarado, who was acclaimed President of Alta California. However, Alvarado entered into negotiations with the Mexican government in 1838, which resulted in the disbandment of the Californio independence movement in favor of greater autonomy and the appointment of Alvarado as governor, thus reestablishing Mexican rule in Alta California, which lasted until 1846.

President of Alta California (1836–1837)

Following the appointments of unpopular governors Gutiérrez and Chico, Juan Bautista Alvarado successfully led a popular uprising of Californios in 1836 which deposed Gutiérrez, proclaimed the independence of Alta California from Mexico, and named Alvarado as its president. Alvarado maintained effective control over California until he entered into negotiations with the Mexican central government in 1837, which resulted in the disbandment of Alta Californian independence in favor of greater autonomy from the Mexican government and recognition of Alvarado as Governor of Alta California.

No.	Portrait	Governor	Took office	Left office	Notes
1st		Juan Bautista Alvarado	1836	1837	Alvarado deposed interim governor Gutiérrez in an 1836 popular uprising of Californios against the Mexican central government and its appointed governors. Alvarado subsequently issued the declaración de la independencia de la Alta California, raised a new flag, and was acclaimed as President of Alta California. Alvarado effectively ruled as President of Alta California from 1836 until he entered into negotiations with the Mexican central government in 1837, whereby he accepted to disband his independence movement in favor of recognition as Governor of Alta California by the Mexican central government and greater autonomy for the Californios.

Mexican governors of Las Californias (1837–47)

While Juan Bautista Alvarado maintained effective control as President of Alta California from 1836 to 1837, the Mexican central government appointed noted Californio statesman Carlos Antonio Carrillo as Governor of California to lead the nationalist offensive against Alvarado. As Carrillo was unsuccessful, Alvarado and the Mexican central government negotiated an end to the civil war in Alta California, resulting in Alvarado's abandonment of independence in favor of greater autonomy and the governorship, thus reestablishing the continuity of Mexican governance over Alta California.

No.	Portrait	Governor	Took office	Left office	Notes
Nominated		Carlos Antonio Carrillo	1837	1837	Carrillo was nominated as governor by the Mexican central government in 1837 to lead nationalists forces to subdue Alvarado's government and reestablish Mexican control over Alta California. As Carrillo was unable to establish effective control over Alta California, the Mexican central government entered into negotiations with Alvarado resulting in his Carrillo's dismissal.
8th		Juan Bautista Alvarado	1837	1842	Following negotiations with the Mexican central government in 1837, Alvarado disbanded his independence movement and was appointed as governor, in exchange for greater autonomy for Californios.
9th		Manuel Micheltorena	1842	1845	Micheltorena was deposed as governor after his defeat at the Battle of Providencia
10th		Pío Pico	1845	1846	In the aftermath of the Battle of Providencia, Pico was acclaimed governor. Following the American Conquest of California, the administration of Alta California came under control of the U.S. Military Governor of California.
Nominated		José María Flores	1846	1847	Flores was nominated as governor following the outbreak of the Mexican–American War and tasked with reclaiming Alta California for Mexico. Despite victories at the Battle of Chino and the Battle of Rancho Domínguez, Flores was unable to reestablish Mexican rule following his defeat at the Battle of Rio San Gabriel and the Battle of La Mesa.
Nominated		Andrés Pico	1847	1847	Pico served as Acting Governor for three days before signing the Treaty of Cahuenga, ending the Conquest of California

American military rule (1846–1849)

Following the American Conquest of California, forces part of the Pacific Squadron and California Battalion established U.S. military rule in California, beginning in 1846. Military governors ruled California until 1849, when efforts led by Bennet C. Riley led to the creation of the Constitution of California at the Constitutional Convention of Monterey and the establishment of civilian rule with the election of Peter Hardeman Burnett as the first governor of California. Soon after, California was admitted as a state.