Thornton, Fife born left half Jock Thomson started his football career with junior club Thornton Rangers in 1923, before moving to Scottish League club Dundee in 1924, where he played for five years and was a member of their 1925 Scottish Cup Final team beaten 2-1 by Celtic at Hampden Park. In October 1929 he was selected by The Scottish League and played in a 4-1 victory over The Irish League at Windsor Park, Belfast before he moved to Everton in March 1930, making his Football League debut against West Ham United the same month.
Described as “an artistic middle man… his tackling is clever and his placing of the ball admirable”, his Everton career had an inauspicious start, with the club suffering relegation in his first season, although he only played 9 matches during the campaign. The following season he was a near ever present missing only one match and he gained a Second Division Championship medal as Everton made an immediate return to the top flight, and then added a League Championship medal in 1932 as Everton won back to back titles, Thomson missing only 3 matches.
In October that year he made his international debut, representing Scotland in a 5-2 home international defeat to Wales at Tynecastle, although this was to prove his only international appearance. He was again a near ever present in their 1932-33 campaign missing only one match and he played in the 1933 FA Cup Final, helping Everton to a 3-0 win against Manchester City at Wembley. He remained a fixture in the team until April 1936 and was an ever present in their 1934-35 campaign. Later in his time at Everton first team appearances became more uncommon for Thomson as he was displaced from the team by Joe Mercer, although he succeeded Billy Cook as club captain for the 1938-39 season, playing 26 times as Everton again won the League Championship. Thomson retired from playing in 1939, having scored 5 goals in 296 appearances for Everton.
Following the Second World War Thomson became manager of Manchester City in November 1947, replacing Sam Cowan. In his first season in charge the club finished tenth in the First Division, though they failed to win any of the final six games of the season. The 1948-49 season saw a slight upturn with a seventh place finish. In October 1949 Thomson made the decision to sign goalkeeperBert Trautmann, attracting criticism for signing a former German paratrooper so soon after the War. Trautmann justified Thomson’s decision by going on to play for the club for 15 years. The 1949-50 season proved to be Thomson’s last. With two thirds of the season gone City had won only five matches. Thomson was dismissed in February 1950, and at the end of season the club were relegated.