The 1981 St. Louis Cardinals season was the franchise's 22nd season in St. Louis and the 62nd in the National Football League. The Cardinals finished the strike-shortened season with a 7-9 record, finishing third in the NFC East. It was Jim Hanifan's second full season as head coach.
The season was divided into two separate parts due to a player's strike that lasted from weeks 3-10. The Cardinals went 1-2 in the first portion of the season. Upon resumption of play, the team improved, going 6-7, but failed to qualify for the expanded 16-team playoff tournament, which featured the top eight teams from each conference after the labor dispute concluded. The season was marked by inconsistency on offense, and despite a defense that ranked in the middle of the league, the team struggled to win close games. Quarterback Neil Lomax continued his development, but the running game remained a challenge. The Cardinals failed to significantly improve upon their 1980 record of 5-11. Key players for the Cardinals during the season included Lomax, running back Ottis Anderson, and defensive end Curtis Greer.