Scott David Westerfeld (born May 5, 1963) is a New York Times bestselling American writer of young adult fiction. He is best known for the Uglies series, set in a future where cosmetic surgery is compulsory at age sixteen, and the Leviathan trilogy, a steampunk retelling of World War I. Uglies will be adapted into a Netflix movie in late 2024, and Leviathan will be an anime series in 2025, also streaming on Netflix.

Westerfeld has authored a total of thirty novels, including five for adults and twenty-five for young adults. His notable works include the Zeroes trilogy, the Midnighters trilogy, and standalone novels such as So Yesterday, Peeps, The Last Days, and Afterworlds.

His books have received numerous accolades, including the Philip K. Dick Special Citation, the Aurealis Award, and the Victorian Premier’s Award. They have been named New York Times Notable Books and BBYA Top Ten Children’s Books of the Year.

Outside of writing, Westerfeld has contributed nonfiction to Nerve, BookForum, and the scientific journal Nature. He has also worked as a ghostwriter, a factory worker, a substitute teacher, a textbook editor, and a software designer. In his artsy days, he wrote music for downtown New York dancers.

Westerfeld was born in Texas, grew up on all three coasts of the US, and attended Vassar. He married writer Justine Larbalestier in 2001, and they split their time between New York City and Sydney, Australia.