 Mitchell started his career with Third Lanark in 1942, spending seven years with the "Hi-Hi" before joining Newcastle United for £16,000 in February 1949.He played for the "Magpies" from 1949 to 1961, becoming something of a cult hero amongst supporters who nicknamed him 'Dazzler'.He was an instrumental part of the team that experienced much success in the 1950s, winning three FA Cups in a five-year period, which included scoring a goal in the 1955 FA Cup Final.