The 1920–21 season was the 26th season of competitive football by Southampton, and the club's first in the Football League. At the end of the previous season, Southampton were one of a host of Southern League clubs elected to make up the new Third Division, finishing second in the inaugural season behind champions Crystal Palace. The Saints began the season strongly, winning seven of their first ten games to begin a lengthy run at the top of the league table until the end of the year. The club began to lose against several teams lower in the table in December, dropping a position as Palace continued to win the majority of their games. Southampton finished the season in second place with 19 wins, 16 draws and seven losses, four points behind the champions and one point ahead of third-placed