Three.
The Steelers had two quarterbacks win the Super Bowl as starters:Terry Bradshaw - IX, X, XIII, XIVBen Roethlisberger - XL, XLIII
The Steelers had 4 number one starting quarterbacks since 1996:Mike Tomczak, Kordell Stewart, Tommy Maddox and Ben Roethlisberger.
Ben Roethlisberger was the starter, Charlie Batch was the back up.
Pittsburgh Steelers
The quarterbacks for the 1975 Super Bowl IX were Pittsburgh Steelers Terry Bradshaw, and Minnesota Vikings Fran Tarkenton.
Terry Bradshaw. He was considered one of the greatest quarterbacks of all time. He played for the Steelers from 1970 to 1983. Watch some old clips and watch in awe of what this man did.
Dick Shiner was the #1 QB for the Steelers in the 1968 and 1969 seasons. The Steelers QBs in the 1967 season were Kent Nix and Bill Nelsen.
Bubby Brister, Neil O'Donnell, Mike Tomczak and Kordell Stewart were the four Steelers starters during that time span.
Troy Smith (Baltimore Ravens) - 12/30/2007 - (27-21)
Ben Roethlisberger was the starting quarterback for the Steelers, and Kurt Warner started for the Cardinals in Super Bowl XLIII.
Kurt Warner for the Arizona Cardinals Ben Roethlisburger for the Pittsburgh Steelers