Reitman's paternal grandfather ran a dry cleaner and then a car wash.[2] His mother is from a Christian background and of French-Canadian descent; she converted to Judaism.

"[8] In the late 1980s, Reitman began appearing in small acting parts and serving as a production assistant on his father's films.

It was Roger Ebert's favorite film of 2007 and received Oscar nominations for Best Picture, Elliot Page's performance as the title character, Diablo Cody's original screenplay, and Reitman himself for Best Director.

Reitman described his production company's goal as being to produce "small subversive comedy that is independent but accessible".

[17] Through Hard C Productions, Reitman is set to produce and direct Banzai Shadowhands, a comedy about "a once-great ninja who is now living a life of mediocrity".

Anatomy has been written by Matthew Spicer and Max Winkler, and will revolve around "a Gotham bookstore clerk who discovers a museum devoted to his life".

[18] Jennifer's Body is a horror comedy written by Diablo Cody and starring Megan Fox, about a cheerleader who is possessed by a demon and starts feeding off the boys in a Minnesota farming town.

In 2001, the year the novel Up in the Air was published, Sheldon Turner discovered the book and wrote a screenplay adaptation, which he sold to DreamWorks in 2003.

Jason Reitman later came upon the novel (initially attracted by the Christopher Buckley blurb on the cover) while browsing in the Los Angeles bookstore Book Soup.

Some of Turner's inventions that were utilized in the final film include Ryan's boilerplate termination speech ("Anyone who ever built an empire or changed the world sat where you're sitting right now..."), a key plot point involving a suicide, and the character of Ryan's partner (written by Turner as male).

Reitman was also an executive producer of the erotic thriller Chloe, theatrically released by Sony Pictures Classics on March 26, 2010.

[28] After the success of the film, both Reitman and his writing partner Gil Kenan had signed an overall deal with Sony Pictures Entertainment to develop more projects.

[29] Reitman was set to return to direct the sequel to Ghostbusters: Afterlife entitled Frozen Empire, but later was replaced by Kenan, who remains as a producer and co-writer in the film, was released in 2024.

Canadian comedian Dan Ackroyd was a member of that SNL cast and describes the film as a "stand alone masterpiece.

Stern, a friend of Ivan Reitman, also revealed that he had seen Jason's early short films and was impressed enough to offer him the opportunity to direct an episode of Son of the Beach (a TV series he produced, a goofy parody of Baywatch), which Jason declined, citing that he was busy obtaining financing for Thank You for Smoking at the time.

Reitman also directed a three-part pretaped sketch for the NBC show Saturday Night Live called "Death by Chocolate," about a walking candy bar, played by episode host Ashton Kutcher, who murders people; stabbing a homeless man, shooting a doctor, cutting off a life support machine on a coma victim and slicing Andy Samberg (dressed as a lumberjack) with a chainsaw.

[33] In 2020, Reitman directed The Princess Bride, a television adaption of novel of the same name for Quibi featuring an ensemble cast to raise money for World Central Kitchen.

[2] In 2000, when he was 23, Reitman started dating his next-door neighbor, writer Michele Lee, with whom he co-wrote the 2004 comedic short Consent.