William Terrell (1778 - July 4, 1855) was a United States Representative from Georgia. Born in Fairfax County, Virginia, he moved with his parents to Georgia, and pursued classical studies. He graduated from the medical department of the University of Pennsylvania at Philadelphia and commenced practice in Sparta, Georgia. He was a member of the Georgia House of Representatives from 1810 to 1813, and held various local offices.
Terrell was elected as a Democratic-Republican to the U.S. House of Representatives, serving in the Fifteenth and Sixteenth Congresses (March 4, 1817-March 3, 1821); he declined to be a candidate for renomination in 1820, and resumed the practice of medicine. He died in Sparta in 1855 and was interred in Sparta Cemetery.
Terrell County, Georgia, created in 1856 from portions of Randolph and Lee Counties, was named for William Terrell.