An infinity pool is also called an infinity edge pool or a zero-edge pool. It is a reflecting or swimming pool where the water flows over one or more edges, producing a visual effect of water with no boundary. Such pools are often designed so that the edge appears to merge with a larger body of water such as the ocean, or with the sky.

Infinity pools require extensive structural, mechanical, and architectural detailing. Since they are often built in precarious locations, sound structural engineering is paramount. The high cost of these pools often arises from the elaborate foundation systems that anchor them to hillsides.