Paul Smiths is located in the southern part of the town of Brighton, between Lower St. Regis Lake to the south and Osgood Pond to the north. It is in southern Franklin County. The CDP limits correspond to the campus of Paul Smith's College.
New York State Route 30 passes Paul Smiths, leading north 32 miles (51 km) to Malone, the Franklin County seat, and south 26 miles (42 km) to Tupper Lake. New York State Route 86 begins at Paul Smiths and leads 12 miles (19 km) southeast to Saranac Lake village.
According to the U.S. Census Bureau, the Paul Smiths CDP has a total area of 0.39 square miles (1.01 km2), of which 0.25 square miles (0.66 km2) is land and 0.14 square miles (0.35 km2), or 34.63%, is water, consisting of part of Lower St. Regis Lake.
The Köppen Climate Classification sub-type for this climate is "Dfb" (Warm Summer Continental Climate).[5] Paul Smiths has a record high of 100, set in July 1936 and a record low of -48, set in January 1912, tying the state record low for January.