Swayne & Hoyt Lines was an American steamship company based in San Francisco, California, and in operation from the late 1890s to the late 1930s.
Swayne & Hoyt was engaged in trade with Japan by 1896, when the company was recorded as protesting duties assessed on ceramic goods it had imported in February 1896.
In the years after World War I, Swayne & Hoyt was engaged in the tramp trade with leased United States Shipping Board ships but later evolved into a scheduled cargo line. In 1926, the company was operating the American-Australian-Orient Line which sailed to Australia, New Zealand, and Asian ports. Also in the mid-1920s, Swayne & Hoyt was engaged in trade between Pacific ports and the east coast of South America.
By the late 1930s, Swayne & Hoyt was engaged in intercoastal shipping between U.S. ports on the Gulf of Mexico and on ports on the Pacific coast via the Panama Canal.