Walder is a surname. Notable people with the surname include:
Albert Walder (born 1957), Italian cross country skier who competed from 1985 to 1988
Chaim Walder (born 1969), bestselling Haredi children's writer
Dave Walder (born 1978), rugby union footballer who plays at fly-half for Wasps
David Walder (1928–1978), British Conservative Party politician
Erick Walder (born 1971), American long jumper
Francis Walder (1906–1997), Belgian writer and soldier
Jay Walder, the Chairman and Chief Executive Officer of the Metropolitan Transportation Authority (MTA) in New York
Katie Walder (born 1982), American actress
Russel Walder (born 1959), American Jazz oboist
Samuel Walder (1879–1946), Australian politician and businessman
Walder Frey, a fictional character in George R.R. Martin's A Song of Fire and Ice
