Walder is a surname and given name. Notable people with the name include:
Surname:
- Albert Walder (born 1957), Italian cross country skier who competed from 1985 to 1988
- Andrew G. Walder (born 1953), American political sociologist
- Chaim Walder (1968–2021), Haredi Israeli children's writer who committed suicide after dozens of sexual assault allegations
- Chris Walder (1900–1997), Dutch footballer
- Christian Walder (born 1991), Austrian World Cup alpine ski racer
- 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
- Fernand Walder (born 1946), Belgian volleyball player
- Francis Walder (1906–1997), Belgian writer and soldier
- George Walder, American football player and coach
- Harald Walder (born 1973), Austrian former snowboarder
- Ingemar Walder (born 1978), Austrian snowboarder
- Jay Walder, the chairman and chief executive officer of the Metropolitan Transportation Authority (MTA) in New York
- Katie Walder (born 1982), American actress
- Marc Walder (born 1965), Swiss journalist, former professional tennis player
- Pius Walder (1952–1982), Austrian lumberjack and poacher
- Russel Walder (born 1959), American jazz oboist
- Samuel Walder (1879–1946), Australian politician and businessman
Given name:
- Walder Frey, a fictional character in George R.R. Martin's A Song of Ice and Fire
- Charles Walder Grinstead (1860–1930), English champion tennis player
- John Walder Dunlop Holder (born 1949), Barbadian Anglican archbishop