If I Had One Wish is a young adult novel by Jackie French Koller, about a teenager named Alex Lansing, whose little brother Stevie is always getting him in trouble. The book was first published in 1991.
One day an old woman grants Alex one wish for his kindness to her. Alex uses it to wish that his little brother Stevie had never been born; to his horror, it comes true. Although no one else remembers Stevie, and Alex's life is in some ways better now, he is still guilt-stricken, and desperately tries to find a way to reverse his wish.
In 2003, the story was adapted as a Disney Channel Original Movie titled You Wish!.