Belly button (or "bellybutton") is a colloquial term for the navel; as a proper noun, it may refer to:

"Belly Button", a song from the Silly Songs with Larry segment of VeggieTales Bellybutton (album), the debut album from the band Jellyfish The Bellybuttons, a comic book series by the French-Canadian team Dubuc and Delaf

See also Bellybutton Nautilus, a species of nautilus.