P.J. Hogan based Muriel's personality on himself, but Muriel's actions were inspired by his sister, who embezzled $15,000 from their father and then disappeared to Sydney to live with a friend.
The writer/director P.J. Hogan wanted to use the music of ABBA in the film. At first, permission for the music to be used was denied. When the director promised to fly to Europe to plead his case to the founders of the band, permission was granted, as long as the band received a percentage of the film profits. The film turned out to be a big international hit, and thus helped inspire the very successful Broadway show which became the movie Mamma Mia! (2008).
Bill Hunter was filming The Adventures of Priscilla, Queen of the Desert (1994) and Muriel's Wedding (1994) at the same time, each requiring him to have different length hair, beard and to be in different parts of the country. Both films developed international cult followings and prominently featured the music of ABBA.
The photographs in the Heslop family album are actual childhood photos of the actors who portray the family.