Haley gave a rousing, freewheeling speech that included a good-natured jabs at everyone from former San Francisco owner Eddie DeBartolo Jr. to Cowboys owner Jerry Jones.
Wolf, who hired Mike Holmgren and traded for Brett Favre shortly after taking over in 1991, led off by praising the core that restored the Packers to legitimacy after two decades of mediocrity.
Polian praised Hall of Fame coach Marv Levy for helping him resurrect the Bills.
Several of Bettis' former teammates, including quarterback Ben Roethlisberger and wide receiver Hines Ward, watched from in front of the stage as the Hall's doors finally opened for the player known simply as "The Bus."
Former Steelers running back Jerome Bettis delivered his speech during Saturday’s festivities. (The Minnesota Star Tribune)
Former NFL player Will Shields poses with his bust during inductions at the Pro Football Hall of Fame on Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Ron Wolf poses with a bust of himself during an induction ceremony at the Pro Football Hall of Fame Saturday, Aug. 8, 2015, in Canton, Ohio. Wolf, the man who brought Brett Favre to Green Bay, beat the quarterback to Canton. Wolf led off the eight-man Pro Football Hall of Fame Class of 2015 on Saturday night. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Former NFL player Charles Haley poses with his bust during inductions at the Pro Football Hall of Fame, Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Sydney Seau, aughter of former NFL player Junior Seau, poses with a bust of her father during inductions at the Pro Football Hall of Fame Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Former President and General Manager of the Indianapolis Colts Bill Polian poses with his bust during an induction ceremony at the Pro Football Hall of Fame Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Former NFL player Tim Brown poses with his bust during inductions at the Pro Football Hall of Fame on Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)
Former NFL player Mick Tingelhoff poses with his bust during inductions at the Pro Football Hall of Fame on Saturday, Aug. 8, 2015, in Canton, Ohio. (AP Photo/Gene J. Puskar) (The Minnesota Star Tribune)