Ivan Reitman (born October 27, 1946 in Komárno in Czechoslovakia, now Slovakia) is a Slovakian-born Canadian film actor, producer, and director. He is best known for the comedies he has directed and produced, especially in the 1980s and 1990s.

Reitman worked on a number of films after graduating from McMaster University in Hamilton, Ontario. He produced two films for director David Cronenberg, Shivers/They Came from Within/The Parasite Murders (1974) and Rabid (1976). His big break came when he produced National Lampoon's Animal House in 1978 and directed Meatballs in 1979. From there, he directed and produced a number of comedies including Stripes (1981), Ghostbusters (1984), Legal Eagles (1986), Twins (1988), Ghostbusters II (1989), Kindergarten Cop (1990), Dave (1993), Junior (1994), Six Days Seven Nights (1998), Evolution (2001) and My Super Ex-Girlfriend (2006).

In the early 1990s, Reitman began to direct fewer films, but increased his role as a producer and executive producer. He helped to produce the animated film Heavy Metal (1981), Spacehunter: Adventures in the Forbidden Zone (1983), Beethoven (1992), Beethoven's 2nd (1993), Space Jam (1996), Private Parts (1997), Road Trip (2000), Old School (2003) Eurotrip (2004) and Trailer Park Boys: The Big Dirty (2006)

Reitman was working on a remake of The Pink Panther in 2005 but backed out. He will next produce the comedy I Love You, Man (2009), starring Paul Rudd and Jason Segel.

Ivan Reitman, as a producer and director, has created many of American cinema's most successful and best loved feature film comedies and has worked with Hollywood's acting elite. Reitman has produced such hits as the ground-breaking sensation National Lampoon's Animal House (1978), which introduced John Belushi to American filmgoers, and the family features Beethoven (1992) and Beethoven's 2nd (1993). His directing credits include Meatballs (1979), Stripes (1981) and Ghost Busters (1984), films starring Bill Murray (I), Dan Aykroyd and Harold Ramis (I); Dave (1993), which starred Kevin Kline and Sigourney Weaver, Junior (1994) which starred Arnold Schwarzenegger, Danny DeVito and Emma Thompson (I). Reitman also produced the HBO telefilm Late Shift, The (1996) (TV), based on Bill Carter (II)'s non-fiction book about the late-night television wars which received seven Emmy nominations. Other recent producing endeavors include Commandments (1997), starring Aidan Quinn (I) and Courteney Cox, Private Parts (1997), starring Howard Stern (I), as well as the animation/ live action film Space Jam (1996), starring Michael Jordan (I) and the Looney Tunes characters. With Twins (1988/I), Reitman created an entirely new comedic persona for action hero Arnold Schwarzenegger -- and forged a personal and professional relationship that continued with Kindergarten Cop (1990) and Junior (1994). Acclaimed dramatic actors such as Robert Redford (I), Debra Winger, Sigourney Weaver, and Emma Thompson (I) have also revealed untapped comic talents under Reitman's direction. In 1984, Reitman was honored as Director of the Year by the National Association of Theater Owners and the next year received a Special Achievement Award at the Canadian Genie awards. In 1979 and again in 1989, for the films Animal House (1978) and Twins (1988/I), Reitman was honored with the People's Choice Award. In November of 1994, Reitman became the third director honored by Variety magazine in a special Billion Dollar Director issue. Reitman was born in Czechoslovakia and fled with his family to Canada at the age of four. He attended Canada's McMaster University, where he produced and directed several television shorts. He followed with a live television show, "Greed" (1999), with Dan Aykroyd as its announcer. "Spellbound," which Reitman produced for the live stage, evolved into the Broadway hit "The Magic Show," starring Doug Henning (I). He continued producing for the stage with the Off-Broadway hit "The National Lampoon Show," and returned to Broadway to produce and direct the musical "Merlin," earning a Tony nomination for directing. Reitman currently heads The Montecito Picture Company, a film and television production company, with partner Tom Pollock (I). His television credits include the Emmy-nominated children's show "Real Ghost Busters, The" (1986) and the Saturday morning animated series "Beethoven" (1994) for CBS. He is presently working on a new animated children's show Mummies Alive! The Legend Begins (1998) (V) and has several feature films in development and pre-production under his new deal with DreamWorks.