D-STAR (Digital Smart Technologies for Amateur Radio) is a digital voice and data protocol specification developed as the result of research by the Japan Amateur Radio League. Other digital technologies are used by amateurs that have come from other services, D-Star is one of the first on-air and packet-based standards to be widely deployed and sold specifically for amateur service use.

D-STAR signals offer clearer signals and use less bandwidth than their non-digital counterparts as long as the signal strength is above a minimum threshold, and no multi-path is occurring, the quality of the data received is better than an analog signal at the same strength. In addition to the over-the-air protocol, D-Star also provides specifications for network connectivity. This enables D-Star radios to be connected to the Internet, other networks, and provides for routing data streams of voice or packet data via amateur radio callsigns.