Music by Victor Herbert
Lyrics by Rida Johnson Young
Date 1910
Source Naughty Marietta (operetta)
Publisher Warner Bros. Inc.

"Ah! Sweet Mystery of Life," from the operetta Naughty Marietta, was perhaps most famously performed by Jeanette MacDonald and Nelson Eddy in the 1935 film of the same name.

Cloris Leachman, Link Hogthrob, and a chorus of pigs sing "Ah! Sweet Mystery of Life" as part of an operetta medley in episode 224 of The Muppet Show. Cloris Leachman had previously performed it in a scene that was deleted from Mel Brooks' film Young Frankenstein.

Wayne and Wanda also performed the song in episode 406.