The Steel Curtain was the defensive line of the 1970s American football team Pittsburgh Steelers of the National Football League (NFL). The line was the backbone of the Steelers dynasty, which won four Super Bowls (IX, X, XIII, and XIV) in six years.

The Steelers began their 1976 season 1–4 and lost their quarterback, Terry Bradshaw. For the nine games remaining in the season, the Steelers recorded five shutouts (three of them uninterrupted), and only allowed two touchdowns (both in a single game), and five field goals. The defense allowed an average 3.1 points per game and the team had an average margin of victory of 22 points. Eight of the Steelers' starting eleven defensive players were selected for the Pro Bowl that year, and four would be selected to the Hall of Fame.