Timothy Tiberius "Timmy" Turner is the main protagonist of the series. His parents are rarely around and take little interest in him, which makes it easy to hide Cosmo, Wanda, and Poof. He wishes for nearly everything he wants, which sometimes causes havoc. 10-year-old Timmy is fairly smart, but has a short attention span, which leads to failing grades (although often his teacher enjoys giving him an F even when he was correct). He marries Trixie (Or Tootie is a possible candidate, since Tammy resembles her) In the episode Channel Chasers and has two children named Tommy and Tammy (which is funny since Tommy is one of the names Trixie or even his parents mistakenly call him during the show). So far, he is one of the only 2D animated characters to have a crossover special with Jimmy Neutron, a 3D animated character. Timmy wears a pink shirt with a pink hat, the reason for this is because Timmy's parents thought he would be a girl.

Timmy longs to be popular and regularly stands up against teachers and bullies, and isn't above torturing his enemies for his own fun. Timmy wishes so many things away that an entire island had to be created as a storage for his "unwished" wishes. He is also shown to be addicted to wishing to the point that he lost nearly all of his resourceful and physical skill and needed to go to "wishing rehab," where he re-learns how to rely on his own skills again. In Fairly OddBaby, Timmy gets a fairy baby brother (who Cosmo has instead of Wanda) who he names Poof. In Wishology, Timmy is revealed in the Cave Prophecy in Fairy World as the one to defeat the Darkness and its forces. Actually it was supposed to be Turbo Thunder, but he fell asleep before the Darkness arrived.

The concept of Timmy first came from series animator Butch Hartman's idea of a male version of Cinderella who is watched over by a fairy godmother