A scuba set is an independent breathing set that provides a scuba diver with the breathing gas necessary to breathe underwater during scuba diving. It is much used for sport diving and some sorts of work diving.

The word SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus. These initials originated in 1939 in the US Navy to refer to US military diver's rebreather sets. As with radar, the acronym has become so familiar that it is often not capitalized and is treated as an ordinary word; for example, it has been taken into the Welsh language as "sgwba".