Snorkeling (British spelling: snorkelling) is the practice of swimming on or through a body of water while equipped with a diving mask, a shaped tube called a snorkel, and usually swimfins. In cooler waters, a wetsuit may also be worn. Use of this equipment allows the snorkeler to observe underwater attractions for extended periods of time with relatively little effort.

Snorkeling is a popular recreational activity, particularly at tropical resort and scuba diving locations. The primary appeal is the opportunity to observe underwater life in a natural setting without the complicated equipment and training required for scuba diving and it appeals to all ages because of how little effort there is, and without the exhaled bubbles of scuba-diving equipment.

Snorkeling is also employed by scuba divers when on the surface, and search and rescue teams may snorkel as part of a water-based search. It is also a means to an end in popular sports such as underwater hockey, underwater ice hockey, underwater rugby and spearfishing.