George Ashmun (December 25, 1804 – July 16, 1870) was a Whig member of the U.S. House of Representatives from Massachusetts.

Ashmun was elected to the U.S. Congress from the Sixth District of Massachusetts in 1844, held office from 1845 to 1851 and was a member of the committees on the judiciary, Indian affairs, and rules.

He opposed the Mexican–American War, and was a strong supporter of Daniel Webster.

After leaving Congress, Ashmun moved to Springfield, Massachusetts, where he spent the rest of his life practicing law in the firm Chapman & Ashmun, founded with Reuben A. Chapman.

There he met newspaper publisher Samuel Bowles (journalist), with whom he helped to found the U.S. Republican Party.