William Wickham Welch (December 10, 1818 - July 30, 1892) was a U.S. Representative from Connecticut.
Born in Norfolk, Connecticut, Welch studied medicine. He was graduated from the medical department of Yale College in 1839 and commenced practice in Norfolk. He served as member of the State house of representatives 1848-1850. He served in the State senate in 1851 and 1852.
Welch was elected as a candidate of the American Party to the Thirty-fourth Congress (March 4, 1855-March 3, 1857). He resumed the practice of his profession. He was again a member of the state House of Representatives in 1869 and 1881. He died in Norfolk, Connecticut, July 30, 1892. He was interred in Center Cemetery.