Ganoga Lake is a natural lake in Colley Township in southeastern Sullivan County in Pennsylvania, United States. Known as Robinson's Lake and Long Pond for most of the 19th century, the lake was purchased by the Ricketts family in the early 1850s and became part of R. Bruce Ricketts' extensive holdings in the area after the American Civil War. The lake is one of the highest in Pennsylvania, which led Ricketts to name it Highland Lake by 1874 and rename it Ganoga Lake in 1881; Pennsylvania senator Charles R. Buckalew suggested the name Ganoga from the Seneca language word for "water on the mountain".