The 1919–20 season was Cardiff City F.C.

's 19th season of competitive football and the team's sixth and final one in the Southern Football League.

They competed in the 22-team Southern Football League First Division, then the third tier of English football, finishing 4th.

For the following season Cardiff were elected to the Football League Second Division following the creation of a new Third Division and the addition of two new places in the Second Division in the Football League.

First team squad.