"Ain't No Fun (Waiting Round To Be A Millionaire)" is a song by Australian hard rock band AC/DC. It is the second track of their Australian album Dirty Deeds Done Dirt Cheap, released in September 1976 (see 1976 in music), and was written by Angus Young, Malcolm Young, and Bon Scott. It is AC/DC's longest studio recording.

"Ain't No Fun (Waiting Round To Be A Millionaire)" is the seventh track on the international version of Dirty Deeds Done Dirt Cheap, released in November 1976. The international version was not released in the United States until April 1981 (see 1981 in music).

The song is written from the point of view of a destitute person who believes he can use rock and roll as a vehicle for success. In addition, the narrator mentions his wife (or girlfriend), who works a full-time job to support him while he follows his dream of rock 'n' roll stardom. The speaker comments that this woman "knows her place." Though the speaker's current reality is grim, he never loses sight of his rock 'n' roll dreams. Scott's lyrics for "Ain't No Fun" are semi-autobiographical, matching a recurring theme in letters he sent to friends through the early days of AC/DC's ascent into stardom. Nonetheless, Scott never seemed to overtly resent that aspect of his chosen profession.

This song is one of very few AC/DC songs to use explicit swearing. At around six minutes, Bon sings the famous lines, "Get your fuckin' Jumbo Jet out of my airport!"