Welland—St. Catharines—Thorold was a federal electoral district represented in the House of Commons of Canada from 1988 to 1997. It was located in the province of Ontario. This riding was created in 1987 from Welland riding. Welland—St. Catharines—Thorold consisted of the southern part of the City of St. Catharines, the City of Thorold and the northern part of the City of Welland. The electoral district was abolished in 1996 when it was re-distributed between Niagara Centre, Niagara Falls and St. Catharines ridings.