A rigid-hulled inflatable boat, (RHIB) or rigid-inflatable boat (RIB) is a light-weight but high-performance and high-capacity boat constructed with a solid, shaped hull and flexible tubes at the gunwale. The design is stable and seaworthy. The inflatable collar allows the vessel to maintain buoyancy even if a large quantity of water is shipped aboard due to bad sea conditions. The RIB is a development of the inflatable boat.

Uses include work boats (supporting shore facilities or larger ships) in trades that operate on the water, as well as use as lifeboats and military craft, where they are used in patrol roles and to transport troops between vessels or ashore.

RIBs are designed with hydroplaning hulls. Due to their low weight, RIBs often outperform some types of similarly sized and powered boats, although a pure fibreglass speedboat with similar dimensions is typically faster, due to its lighter weight and more arrowlike-shape.

RIBs can also generally cope better with rougher seas, although this may be partially due to an increased level of confidence, in knowing that a RIB is hard to sink, and better absorption of heavy loads by the flexible tubes, which therefore make heavy seas less unpleasant^[5].

The maximum speed of the RIB depends on its gross weight, power, length and profile of hull, and sea conditions. A typical seaborne 6-metre (19 ft 8 in) RIB, with six passengers, 110 horsepower (82 kW) engines, in Beaufort force 2 is very likely to have a top speed of around 30 knots (56 km/h). High-Performance RIBs may operate with a speed between 40 and 70 knots (74 and 130 km/h), depending on the size and weight.