Reason for Saying
Woo-hoo! is a catchphrase used by Homer. He uses it when he is happy. It is often followed by a D'oh!. In one episode, he is seen going, "D'oh! D'oh! D'oh! Woo-Hoo! D'oh! D'oh! D'oh! D'oh! D'oh! D'oh! Woo-Hoo!" while a roulette wheel spins around. When it gets to 17, his number, he says, "Woo-Hoo!" In another, he says it, but when Marge protests, he says, "I said, 'Woo-Hoo,'" in the same tone. In Mona Leaves-a, Mona says in her will that she will give Homer the best thing, to which Homer replies, "Woo-Hoo!".
Used in other media
Homer learns he can get autographs from the Mexican and Portuguese soccer players in "
The Cartridge Family
Homer learns that he can fly throughout the continental United States for free in "
Fear of Flying
Homer hears that one of his lottery numbers is part of the winning combination (even though his others aren't) in "
Homer's grease enterprise makes money (though not actually a profit) in "
Lard of the Dance
A young Homer sticks multiple crayons in his nose in "
Homer imagines himself winning a sports bet in "
Homer's reaction when the pranks Mr. Burns orders him to do are successful in "
Homer vs. Dignity
Homer after Mr. Burns decides to buy liposuction for him in "
Homer and Bart after learning that Marge, Lisa and Maggie will be away for a week in "
Bart After Dark
Homer says the catchphrase in a somber tone after inheriting an estate from a deceased relative in "
Bart the Fink
Homer's response when Marge's painting of him wins first prize in a contest in "
Brush with Greatness
Homer when Marge tells him she is giving something to read (though he is disappointed when he learns it's a book) in "
Kiss Kiss Bang Bangalore
Homer's response to Marge inviting him to the ballet (despite his not knowing what ballet is) in "
Marge on the Lam
Homer realizes his family possesses Mr. Burns' long-lost teddy bear
Teenage Homer's offer to take Marge to prom is accepted in "
The Way We Was
Homer thinks Abe has forgiven him in "