Inflatable boat is a lightweight boat constructed with its sides and bow made of flexible tubes containing pressurised gas. For smaller boats, the floor and hull beneath it is often flexible. On boats longer than 3 metres / 9.8 feet, the floor often consists of three to five rigid plywood or aluminium sheets fixed between the tubes but not joined rigidly together. Often the transom is rigid, providing a location and structure for mounting an outboard motor.

Some inflatable boats have been designed to be disassembled and packed into in a small volume, so they can easily stored and transported to water when needed. Here the boat when inflated is kept rigid crossways by a foldable removable thwart. This feature allows such boats to be used as liferafts for larger boats or aircraft, and for travel or recreational purposes.

Inflatable boats may have rubber floors, either plain or inflatable, or they may include steel, wood or aluminium sheets for rigidity. The tubes are made of rubberised, synthetic sheets of Hypalon or PVC to provide light-weight and secure buoyancy. The tubes are often constructed in separate sections, each with a valve to add or remove air, to reduce the effect of a puncture.

Some inflatable boats have an inflated keel to create a "groove" along the line of the hull improving the hull's wave cutting and turning performance. Due to the lightness, it is easy to cause an inflatable boat to start hydroplaning, thus making it faster than the engine would allow when the hull is operating in displacement mode.

A growing use for inflatables is for white water rafting and kayaking, as well as in river, lake and ocean touring. Professional-level rafts and kayaks have existed for many years; since the late 1990s, more affordable inflatable rafts, kayaks (including sea kayaks) and canoes have been developed by European and North American companies. Typically these inflatable boats contain no rigid frame members, so they can be deflated, folded and stored in compact bags.