A lazy river is a water ride found in water parks, hotels, resorts, and recreation centers. It usually consists of a shallow pool that flows similarly to a river, with a slow current that is just enough to allow guests to gently ride along lying on rafts. The current is generated by means of a gradual slope in the terrain, aided by a pumping mechanism that allows for the river to continue flowing infinitely. Lazy rivers may also have scenic elements added, such as small waterfalls on the edge of the river. Some lazy rivers connect or lead into swimming pools or wave pools, while others are self-contained courses that simply complete a circuit.

Lazy rivers use jets and pumps to create a continuous current throughout the length of the attraction. The most significant difference between lazy rivers and pools, spas, fountains, and other similar water features is that lazy rivers typically have far more of them and require much more careful placements and strength to operate efficiently. While many lazy rivers exist as a loop, allowing for an infinite series of laps around the body of water, other options exist to create a more linear experience.

Lazy rivers are a popular choice for many locations, including water parks, hotels, and high-end resorts. They offer a relaxing experience where people can float along a winding current in a tube, letting the gentle flow carry away their cares as they bask in the sun. Lazy rivers are also available in residential areas so that people can create, customize, and enjoy their own lazy river experience.