William Colin Alexander (14 September 1907 – 8 February 1993) was an Australian cricketer who played first-class cricket from 1925 to 1929. A middle-order batsman, Alexander made his first-class debut for South Australia in the 1925-26 season a few weeks after turning 18. In his second match, against the touring New Zealanders, he scored 130 and 34 not out. In his next match, which was his first in the Sheffield Shield, he scored 133 against Victoria. In the 1926-27 season he scored 55 and 104 against New South Wales, and he was selected to play for The Rest against Australia at the end of the season.