Ballyfin (Baile Fionn in Irish, meaning "Town of Fionn") is a small town and parish in County Laois, Republic of Ireland. Located in the Slieve Bloom Mountains, the town is near the midlands of Ireland.

According to legend, Fionn Mac Cumhaill is said to have been raised here. Fionn ate the Salmon of Knowledge which gave him untold knowledge. Later he became leader of the Fianna. Ballyfin is also famous for Ballyfin House, now the Patrician College.

Ballyfin National School celebrated 100 years in 2002. The town also has many excellent Gaelic Athletic Association teams. As Ballyfin is situated in the Slieve Blooms there are many beautiful walks quite nearby.

See also: List of towns in the Republic of Ireland