Lost in Oz is a trilogy of novels by American author Joshua Patrick Dudley, founded on and continuing the famous Oz stores by L. Frank Baum.

Lost in Oz and its two sequels relate the adventures of Joshua, Tamara, Tommy, Laura and Maria as they discover their destiny in Oz as the Guardians of Oz.

The Guardians of Oz is the sequel series to Lost in Oz and also introduces Patricia, Lorraine, Rose-Marie and Wendy as the former Guardians of Oz and continues the stories of Joshua, Tamara, Laura and Maria.

Tommy's story is continued in the sequel Lost in Wonderland.