In real life, Dan Devine was very supportive of Rudy and elected to put him in the game on his own. Because Devine considered Rudy a friend, he volunteered to play a villain in order to get the film greenlit.
In the movie, Rudy is portrayed as having largely gone into the steel industry after graduating high school. In reality, he served four years in the U.S. Navy as a yeoman on a communications ship, which is never mentioned.
Many of the priests and miscellaneous Notre Dame employees in the movie are actual Notre Dame employees.
The crowd scene when Rudy is cheering in the stands is a real game between Notre Dame and Penn State, which was played in the snow during the 1992 season. You can even see fans with Penn State hats sitting around Rudy.
The football scenes have an added sense of realism because director David Anspaugh never filmed any scenes with a camera on the field. As with a broadcast of a real game, all football scenes were filmed with off-field cameras.
Daniel 'Rudy' Ruettiger: In the final six minutes of the film, the real-life Rudy as a Notre Dame fan sitting in the football stands. While the crowd is shouting "Rudy, Rudy," the camera points to the crowd then cuts to a close-up of Rudy's "father" and "brother." Daniel 'Rudy' Ruettiger can be seen to the left of his "father" (Ned Beatty). Rudy is wearing a plaid driving cap and a dark coat with a white fur collar. Later during the cheering, his father turns and playfully bats at the real Rudy.
Theodore Hesburgh, Edmund Joyce: In the middle of the film, during the scene in which Father Cavanaugh speaks to Rudy in the Basilica, Notre Dame President Emeritus Father Theodore Hesburgh and Edmund (Ned) Joyce, Hesburgh's Vice-President, makes a cameo appearance. They are seen at the beginning of the scene walking in the Basilica to the right side of Father Cavanaugh's character. Father Hesburgh was President when the real Rudy Ruettiger attended Notre Dame. The Joyce Athletic and Convocation Center, on the Notre Dame Campus, was named after Ned Joyce.