The outfit, worn by Bert Lahr in the classic movie, has been reunited with the ruby slippers and pinafore dress Judy Garland wore as Dorothy in the film for the Icons of Hollywood sale at Profiles in History in California, scheduled for 15 and 16 December (11).
Profiles boss Joe Maddalena tells WENN, "This costume was worn when the Cowardly Lion first meets Dorothy on the Yellow Brick Road and sings If I Only Had the Nerve... Just like the ruby slippers we offer in the same auction that Dorothy wore when she clicked her heels together and returned to Kansas, this Cowardly Lion costume is very special because it was worn in some of the most magical moments of the film. It is one of only two known costumes worn by Bert Lahr."
The costume, made from an actual lion hide, is expected to sell for more than $2 million (£1.25 million).
Other items going under the hammer at the auction include the lavish trailer Elizabeth Taylor used as a home from home on the set of 1963 movie Cleopatra; Taylor and Eddie Fisher's marriage license from their Las Vegas wedding; Steve McQueen's two-piece Gulf racing suit from film classic Le Mans; Marilyn Monroe's wedding ring; Bela Lugosi's Count Dracula cape, and the DeLorean sports car from Back to the Future III.