Archibald Alexander Ritchie (28 January 1806 – 9 July 1856) was an American ship captain, China trader, and California businessman.

His father, Hugh Ritchie, married Esther Alexander, of a family that had emigrated to Virginia in 1737.

The company traded hides, tallow and otter skins from California in exchange for goods from China.

[2] Ritchie wrote in 1851 to his wife Martha, who was living in New Castle, Delaware,[1] You can’t imagine what lovely country and climate this is ...

Ritchie noted that the squatters in Suisun included "men of means, lawyers, doctors, with fine farms and families".

In 1852 Ritchie and Paul S. Forbes filed claims for the Guenoc and Collayomi properties under the new land title laws established with California’s statehood.

Ritchie had bought a lot in Benicia in 1850, which he promoted as the state capital, and built a fine house there.

In 1856 Ritchie backed John Nugent of the San Francisco Herald in his attacks on the Second Vigilance Committee.

[2] Ritchie was buried in the Yerba Buena Cemetery, and his body was later moved to Laurel Hill.

[2] After another move, he is now buried in Cypress Lawn Memorial Park, Colma, San Mateo County, California.

By 1870 the Ritchie family had started to split the Guenoc property into smaller units that were offered for sale, and the south of Lake County began to be developed.