Katherine Applegate is an American writer who began her career writing for the Sweet Valley Twins series. Applegate began publishing her own novels in 1991. Applegate is best known for her young adult and children’s adventure and science fiction series, including Anamorphs and Remnants. Publishing prolifically under both pseudonyms and her own name, Applegate has authored multiple picture books, several Disney novels, and both adult and teen romances, winning multiple awards for her writing. In 2008, she won the Golden Kite Award and the Bank Street 2008 Josette Frank Award for Home of the Brave, as well as earning the distinction of being a Judy Lopez Memorial Award honor book. In 2013, Applegate won the very prestigious Newbery Medal for The One and Only Ivan.

Applegate is married to fellow writer Michael Grant, who coauthored some of her Anamorphs and Everworld novels. The two have lived in many places, including Italy, Florida, Texas, and California. They have two children together.