Aquaphilia is a form of sexual fetishism that involves images of people swimming or posing underwater, and sexual activity in or under water.

Literally "water lover" from the Latin aqua and Greek φιλειν (philein), the term "aquaphile" was first used by Phil Bolton, when he created the "Aquaphiles Journal" - an online magazine for followers of the underwater erotica scene published in the 1990s.

The psychology of aquaphilia was the subject of a paper by Corinne Lamberth (a therapeutic counsellor based in Lewisham, South London) in 1998. A copy of this paper was published in the Aquaphiles Journal in early 1999.