Nicholson Township is a township in Fayette County, Pennsylvania, United States. The population was 1,730 at the 2020 census, a decline from the figure of 1,805 tabulated in 2010. The Albert Gallatin Area School District serves the township. New Geneva, Martin, Gallatin, Old Frame, Bowood, Woodside, and Grays Landing are communities in the township.

Pennsylvania Route 166 is a north–south state highway in Fayette County, Pennsylvania. It follows the path of the Monongahela River along the entire western border of Fayette County.