Behaviour is the sixth studio album by the Canadian progressive rock band Saga, and was originally released in 1985, two years after the moderately successful Heads or Tales.

Behaviour was itself successful, and managed to outsell its 1983 predecessor thanks to the strong performance of the single "What Do I Know?"

[4] The album contains singer Michael Sadler's most personal song, "(Goodbye) Once Upon a Time", which he said was written about his late father and which still brought up strong emotions when performed years after the album's release.

There was an overhaul of both the sounds and styles incorporated by the band during the development of the new album, leading Saga to produce a more pop-oriented sound than their previous progressive rock works.

After the album was released, singer Michael Sadler informed drummer Steve Negus and Jim Gilmour that they were no longer welcome in the band, beginning a rift in the band that lasted until 1991.