William Welch may refer to:
- William C. Welch (born 1977), American professional wrestler for the CZW
- William Welch (cricketer, born 1907) (1907–1983), Australian cricketer
- William Welch (cricketer, born 1911) (1911–1940), Australian cricketer
- William Welch (printer), U.S. manufacturer
- William Welch II, former Chief of the Public Integrity Section of the DOJ Criminal Division
- William A. Welch (1868–1941), American engineer and environmentalist
- William H. Welch (1850–1934), founder of Johns Hopkins Medical School and instrumental reformer of medical education in the United States
- William Welsh (actor) (1870–1946), or William Welch, American actor
- William H. Welch (judge) (1805–1863), fourth and last Chief Justice of the Supreme Court of Minnesota Territory
- William H. Welch, known as Wilton Welch (born 1884) Australian actor, dramatist, director
- William Welch (designer) (born 1972), English industrial designer
- William W. Welch (1818–1892), member of the U.S. House of Representatives from Connecticut
- William Neville Welch (1906–1999), Church of England bishop