St. Regis Falls is a census-designated place (CDP) in Waverly, Franklin County, New York, United States. As of the 2020 census, St. Regis Falls had a population of 432.
St. Regis Falls is located at the northern end of the town of Waverly, along the north side of the St. Regis River, a tributary of the St. Lawrence River. The falls for which the community is named are on the river at the western end of town. According to the United States Census Bureau, the CDP has a total area of , all land.
New York State Route 458 passes through the community, leading west to Nicholville and southeast to Santa Clara. Potsdam is to the west via Routes 458 and 11B, while Paul Smiths is to the southeast via Routes 458 and 30.
The northern border of the CDP follows the Waverly/Dickinson town line.
Saint Regis Falls Central School is located in the northern part of the CDP, serving the town of Waverly and surrounding towns.
The marshy area east of the village where the water meets Duane Street (Red Tavern Road) on both sides just before Trim Hill is often referred to as Alligator Alley.
The school district is St. Regis Falls Central School District.