Gideon Jacques Denny (1830–1886) was a marine artist who was born in Wilmington, Delaware on July 15, 1830.
As a young man, he worked on ships in the Chesapeake Bay.
After two years in California, he moved to Milwaukee, where he studied painting with Samuel Marsden Brookes.
After six years of study in Milwaukee, Denny returned to San Francisco and established a studio on Bush Street.
In 1862, Brookes moved to San Francisco and shared a studio with Denny.