When I Was Young in the Mountains is a 1982 children's book. It was the first book written by Cynthia Rylant, who has written over 60 children's books such as Missing May, which won the Newbery Medal. The book, which Rylant later said took her but an hour to complete, earned an American Book Award in 1982 and Diane Goode's illustrations won it a Caldecott Honor.

The book tells the story of the main character's youth in West Virginia, in the Appalachian Mountains. The book is based on Rylant's real life.