The Secret of NIMH is a 1982 American animated fantasy adventure film directed by Don Bluth in his directorial debut and based on Robert C. O'Brien's 1971 children's novel, Mrs. Frisby and the Rats of NIMH. The film features the voices of Elizabeth Hartman, Peter Strauss, Arthur Malet, Dom DeLuise, John Carradine, Derek Jacobi, Hermione Baddeley, and Paul Shenar. It is produced by Bluth's production company Don Bluth Productions in association with Aurora Productions.
The Secret of NIMH was released in the United States on July 16, 1982, by MGM/UA Entertainment Co. under the United Artists label. It was followed in 1998 by a direct-to-video sequel, The Secret of NIMH 2: Timmy to the Rescue, which was made without Bluth's involvement or input and met with poor reception.
Critics Gene Siskel and Roger Ebert gave the movie two positive "yes" votes on a July 15, 1982, episode of their television program Sneak Previews, with Ebert stating "Walt Disney would've liked The Secret of NIMH". In his print review for the Chicago Sun-Times, Ebert gave the film three out of four stars, calling it "an artistic success", praising the quality of its animation and that it "contains that absolute rarity among feature-length animated cartoons, an interesting premise".