Almost became the Razzies nominee of Worst Actor category as his name was included on the 2005 Razzie Award nominating ballot for his roles in "The Alamo" and "The Day After Tomorrow" which both came up in 2004.
Took triple job as actor, writer, and director in "Shame on You" (2008).
Admitted that he suffered from anorexia in the mid '90s when preparing his role in "Wyatt Earp" (1994) during a 2006 interview with Best Life Magazine.
Was selected as the Top Golfer among the "Hollywood Set" by Golf Digest in 2005.
His son, Jack, served as the best man for his third wedding with Kimberly Buffington in 2004.
Lost 40 pounds of his weight to make a convincing portrayal of Doc Holliday in "Wyatt Earp" (1994).
Turned down the role of Josh in "Big" (1988), Stephen 'Bull' McCaffrey in "Backdraft" (1991), and Thomas Wayne in "Batman Begins" (2005).
Appeared together with brother Randy Quaid in an off-Broadway production of Sam Shepard's "True West" in 1984.
Had written songs for his 3 films of "The Night the Lights Went Out in Georgia" (1981), "Tough Enough" (1983), and "The Big Easy" (1987).
Was considered for the role of Luke Duke in TV series "The Dukes of Hazzard" (1979-1985).
Actually was offered to play Bob in "Halloween" (1978) because his then-girlfriend P.J. Soles was in the film, but had to decline it due to scheduling conflict.
Took part in his college stage production of "Bus Stop" (1974).
Appeared as an impressionist in Houston nightclubs at the age of 15.
His parents divorced when he was in high school.
Is a big fan of Phish and has been seen attending several of the band's concerts.
His drama teacher at Bellaire High School and the University of Houston was the same man named Cecil Pickett, the father of Cindy Pickett.
Loves playing golf and his handicap is 6.
Likes to perform barefoot onstage when singing in order to evoke the feeling of comfort as if he was playing in his living room.
Is actively involved in charity for New Orleans' International Hospital for Children.
Has also developed a career as musician under his band, Dennis Quaid and the Sharks.
Is a member of Beverly Hills' Bel-Air Country Club.
His most favorite director is David Lean and once being scheduled to appear in his film project of "Nostromo" in 1991, but the production was cancelled upon the helmer's death.
Is a licensed private pilot with either single or multiengine instrument ratings and has a type rating for the Cessna Citation 500 series twin-engine light jet which he regularly uses to visit his property in Montana.
Is Evi Quaid's brother-in-law and Gene Autry's cousin.