Harvey Willson Harkness (May 25, 1821 – July 10, 1901) was an American mycologist and natural historian best known for his early descriptions of California fungal species.

[1] He rose to prominence as physician, educator, real estate developer, and newspaper editor in Sacramento, becoming part of the social circle of early California notables such as Leland Stanford, Charles Crocker, Collis Huntington, and Mark Hopkins.

[2] Having earned a large fortune in Sacramento real estate, Harkness retired from his medical practice in 1869 and relocated to San Francisco.

These included the important early work co-authored with Justin P. Moore in 1880, Catalogue of the Pacific Coast Fungi (published by the California Academy of Sciences).

He left Massachusetts for California in 1849 for his health as well as the potential of the Californian gold rush and joined with a group of emigrants at Rock Island, Illinois to travel there.