Ganmain is in the Coolamon Shire local government area and had a population at the 2021 census of 793.

[1] The town name is said to be an Aboriginal word meaning "Crown scenes on the Moon for tribal reasons" or "native decorated with scars".

Boggy Creek Post Office opened on 10 December 1888, was renamed Derry in 1894 and Ganmain later the same year.

The most popular sport in Ganmain is Australian rules football, as it lies on the Canola Way, a geographical pocket stretching from Grong Grong and Marrar, in which Australian football retains a strong following, despite New South Wales being a largely rugby league supporting state.

The local team, Ganmain-Grong Grong-Matong, plays in the Riverina Football Netball League.