For a QB that was truly a backup (second string), that would be Earl Morrall who was second string for the 1970 Baltimore Colts that won Super Bowl V and the 1972 and 1973 Miami Dolphins who won Super Bowls VII and VIII. Morrall started 11 games (9 regular season, 2 playoff) in the 1972 season when Bob Griese went down with leg and ankle injuries but went back to second string when Griese was declared the starter for the Super Bowl. Morrall also took over for John Unitas in Super Bowl V when Unitas went down with a rib injury. Many QBs have won two rings as a backup. Steve Young of the San Francisco 49ers won rings in Super Bowls XXIII and XXIV as a backup and Super Bowl XXIX as a starter. Zeke Bratkowski of the Green Bay Packers won rings in Super Bowls I and II. Joe Gilliam and Terry Hanratty of the Pittsburgh Steelers won rings as backups in Super Bowls IX and X. Cliff Stoudt and Mike Kruczek won rings as backups for the Steelers in Super Bowls XIII and XIV. Jason Garrett of the Dallas Cowboys won rings as a backup in Super Bowls XXVIII and XXX. Gary Kubiak of the Denver Broncos won rings as a backup in Super Bowls XXXII and XXXIII. Rohan Davey of the New England Patriots won rings as a backup in Super Bowls XXXVIII and XXXIX.
Mike Kruczek was the backup quarterback for the Steelers in Super Bowl XIV.
Super Bowl VI as a backup quarterback for the Dallas Cowboys.
Dan marino
Cliff Stoudt won 2 Super Bowl rings as a backup quarterback with the Steelers in Super Bowls XIII & XIV. Charlie Batch also has 2 Super Bowl rings (XL & XLIII) with only playing two games during the 2005 season and no games during the 2008 season.
Gale Gilbert was a backup quarterback for the Buffalo Bills for the four years they went to the Super Bowl and lost (Super Bowls XXV-XXVIII) and was the backup quarterback for the San Diego Chargers in Super Bowl XXIX.
4
1 ... as the quarterback for the Redskins that defeated the Dolphins in Super Bowl XVII.
Tom Brady
two
Assuming you are refering to Super Bowl Rings, the answer is Troy Aikman.
Tom Brady, with three.
No quarterback from USC has started and won a Super Bowl but there have been a couple that won as backups. Rob Johnson was the backup QB for the 2002 Tampa Bay Buccaneers that won Super Bowl XXXVII. Mike Rae was the backup QB for the 1976 Oakland Raiders that won Super Bowl XI.