The Doomsday Defense was the nickname given to the famous defense of the Dallas Cowboys American football team during the dynasty years of the late 1960s - 1970s. This defense was the backbone of the Cowboys' dynasty, which won two Super Bowls (VI, XII) and played in three more (V, X and XIII).
The Doomsday Defense is often recognized as having two different "generations," but there is no universally agreed-upon definition of exactly when those defenses existed or who their members were, which is why different listings of players and time periods exist. The original "Doomsday Defense" can generally be identified as the Cowboys' defenses from 1966 to 1975. "Doomsday II" had its heyday from approximately 1976 to 1982. Many Cowboy fans recognize the defense from 1992-1996 as "Doomsday III", though to a lesser extent. This defense was in part, responsible for the Cowboys being the first team to ever win 3 Super Bowls in a four year span.
The first defensive player to be named Most Valuable Player of the Super Bowl was linebacker Chuck Howley (V). Later linemen Harvey Martin and Randy White became the first (and only) teammates (co-MVPs) to win the award (XII).
- #71 - Willie Townes / #63 - Larry Cole
- #75 - Jethro Pugh
- #74 - Bob "Mr. Cowboy" Lilly (NFL 1960s All-Decade Team; NFL 1970s All-Decade Team; Hall of Fame; Ring of Honor)
- #66 - George Andrie
- #54 - Chuck Howley (Ring of Honor)
- #55 - Lee Roy Jordan (Ring of Honor)
- #52 - Dave Edwards / #50 - D. D. Lewis
- #34 - Cornell Green
- #20 - Mel Renfro (Hall of Fame; Ring of Honor)
- #27 - Mike Gaechter / #41 - Charlie Waters
- #26 - Herb Adderley (Hall of Fame; NFL 1960s All-Decade Team) / #43 - Cliff Harris (Ring of Honor)
"Doomsday II" 
- #79 - Harvey Martin (NFL 1970s All-Decade Team; 1977 NFL Defensive Player of the Year)
- #63 - Larry Cole / #78 - John Dutton
- #54 - Randy "The Manster" White (Hall of Fame; Ring of Honor)
- #72 - Ed "Too Tall" Jones
- #31 - Benny Barnes
- #43 - Cliff Harris (NFL 1970s All-Decade Team; Ring of Honor) / #26 - Michael Downs
- #41 - Charlie Waters
- #24 - Everson Walls / #25 - Aaron Kyle