William Grant Stratton (February 26, 1914 – March 2, 2001), known as "Billy the Kid", was the 32nd Governor of Illinois from 1953 to 1961, succeeding Adlai Stevenson II in that office. He was born on February 26, 1914 in Ingleside in Lake County, Illinois, the son of William J. Stratton, an Illinois politician, and Zula Van Wormer Stratton, he served two non-consecutive terms as an at-large Congressman from Illinois, elected in 1940 and 1946. He was elected Illinois State Treasurer in 1944 and 1950. He won the Republican nomination for governor in 1952, then defeated Lt. Governor Sherwood Dixon to become the youngest governor in America at that time.
In 1960, Governor Stratton ran for an unprecedented third-consecutive term but was defeated by Otto Kerner, Jr.
He was acquitted of charges of tax evasion in 1965.
In 1968 he ran in the Republican primary for Governor of Illinois and was defeated by Richard B. Ogilvie.
In retirement, Stratton resided in Chicago.
At the time of his death, he was a member of the Illinois Civil Service Commission. He died at the Northwestern Memorial Hospital in Chicago, Illinois on March 2, 2001, aged 87. Among his pall bearers were his successors as Governor, James R. Thompson, Jim Edgar, and George H. Ryan.
The following are named in his honor:
- William G. Stratton Lock and Dam on the Fox River (Illinois) near McHenry, Illinois
- William G. Stratton State Park on the Illinois River in Morris, Illinois
- William G. Stratton Building (formerly State Office Building) in the Illinois State Capitol complex, which houses offices of many state legislators and other state agencies and was completed during his first term as governor
- Stratton Quadrangle at Southern Illinois University at Edwardsville in recognition of his position as governor at the time of the university's founding. He was also the speaker at SIUE's first commencement in 1960.