Southampton was elected to the Football League and in the 1921-22 season they won the Third Division South championship. He was also in the team that reached the 1925 semi-final against Sheffield United. Unfortunately for Parker the club lost the game 2-0.
Parker played in over 200 league games for Southampton before joining Arsenal in March 1926. At the time the team included Charlie Buchan, Andy Neil, Jimmy Ramsey, Jimmy Brain, Joe Hulme and Billy Blyth.
Herbert Chapman recognised Parker's leadership qualities and made him captain of the side. Henry Norris refused to allow Chapman to spend too much money to strengthen his team and in the 1926-27 season Arsenal finished in 11th position. However, they did enjoy a good run in the FA Cup. They beat Port Vale (0-1), Liverpool (2-0), Wolverhampton Wanderers (1-0) and Southampton (2-1) to reach the final at Wembley against Cardiff City. Arsenal lost the final 1-0.
Herbert Chapman gradually adapted the "WM" formation that had originally been suggested by Charlie Buchan. Chapman used his full-backs to mark the wingers (that job had previously been done by the wing-halves). He also developed what became known as the counter-attacking game. This relied on the passing ability of Alex James and goalscoring forwards like David Jack, Jimmy Brain, Joe Hulme, Cliff Bastin and Jack Lambert. Chapman also built up a good defence that included players such as Tom Parker, Bob John, Eddie Hapgood, Herbert Roberts, Alf Baker and George Male.
Success was not immediate and Arsenal finished in 14th place in the 1929-30 season. They did much better in the FA Cup. Arsenal beat Birmingham City (1-0), Middlesbrough (2-0), West Ham United (3-0) and Hull City (1-0) to reach the final against Chapman's old club, Huddersfield Town. At the age of 18 years and 43 days, Cliff Bastin was the youngest player to appear in a FA Cup Final. Arsenal won the game 2-0 with goals from Alex James and Jack Lambert.
The following season Arsenal won their first ever First Division Championship with a record 66 points. The Gunners only lost four games that season. Jack Lambert was top-scorer with 38 goals. Parker only missed one league game that season. Other important players in the team included Frank Moss, Alex James, David Jack, Cliff Bastin, Joe Hulme, Eddie Hapgood, Bob John, Jimmy Brain, Herbert Roberts, and Alf Baker.
George Male eventually replaced Parker and in March 1933 he became player-manager of Norwich City. In his first season he guided the club to the Third Division South title. In 1937 he became manager of Southampton.
Tom Parker died in 1st November 1987.