Walter Brocton Kay
- Bats Left, Throws Right
- Height 6' 2", Weight 180 lb.
- School Roanoke College
- Debut August 12, 1907
- Final Game October 5, 1907
- Born February 14, 1878 in New Castle, VA USA
- Died December 3, 1945 in Roanoke, VA USA
King Bill Kay had the highest batting average on the 1907 Senators, a last-place team, in his only year in the majors.
He later went on to play many years for teams in New York state such as Albany and Binghamton. The SABR Minor League database shows him playing in the minors for 15 years after his major league time. He led the New York State League in batting average in both 1909-10 as well as in 1915-16. In 1910 he beat out Harry Lumley, who placed second. He holds a number of New York State League hitting records.