Water skiing (also waterskiing or water-skiing) is a surface water sport in which an individual is pulled behind a boat or a cable ski installation over a body of water, skimming the surface on two skis or one ski. The sport requires sufficient area on a stretch of water, one or two skis, a tow boat with tow rope, two or three people (depending on local boating laws), and a personal flotation device. In addition, the skier must have adequate upper and lower body strength, muscular endurance, and good balance.

There are many options for recreational or competitive water skiers. These include speed skiing, trick skiing, show skiing, slaloming, jumping, barefoot skiing and wakeski. Similar, related sports are wakeboarding, kneeboarding,[5] discing, tubing, and sit-down hydrofoil.