Butch Hartman initially declined an offer from Fred Seibert to pitch ideas for Oh Yeah! Cartoons, but changed his mind after finishing his work on Johnny Bravo and decided to create his own series.

Hartman came up with the entire premise of the show in about fifteen minutes, first drawing the fairy who would become Wanda (originally named Venus) before creating Cosmo, since he had never heard of a 'fairy godfather' before.

Timmy Turner was originally going to be named Mike after Hartman's brother, but after the two had a fight, Hartman named the character Timmy after his other brother instead.

Hartman originally planned to give Timmy science-based powers, but dropped the idea because Dexter's Laboratory had just come out, opting for a magical fairy premise instead.

The series went through several working titles during development, including The Fairy GodParents and Oh My GodParents, before Bill Burnett suggested the final title The Fairly OddParents.

The show was rejected by both Hanna-Barbera and Cartoon Network before Hartman successfully pitched it to Nickelodeon as part of Oh Yeah! Cartoons.

Timmy Turner was voiced by Mary Kay Bergman in the original Oh Yeah! Cartoons shorts; Tara Strong later re-dubbed Bergman's dialogue in those shorts to maintain vocal continuity with the full series, where Strong voiced Timmy.

In the early Oh Yeah! shorts, Timmy's parents were only shown from the neck down with their faces hidden, and character traits differed notably from the later series—Cosmo was more intelligent while Wanda was ditzy, and Vicky was less evil and originally had a little brother instead of a sister.

A planned spin-off series called Crash Nebula, based on the fictional show Timmy watches, had its pilot air during season five, but Nickelodeon declined to pick it up; a planned Crash Nebula movie for Paramount was also canceled due to similarities with Disney's Sky High.

The Fairly OddParents briefly overtook SpongeBob SquarePants as the number one highest-rated children's television program in mid-2003, and drew a notably wide audience including 10.8 million adult viewers per week.