An amateur radio net, or simply ham net, is an “on-the-air” gathering of amateur radio operators. Most nets convene on a regular schedule and specific frequency, and are organized for a particular purpose, such as relaying messages, discussing a common topic of interest, in severe weather (for example, during a Skywarn activation), emergencies, or simply as a regular gathering of friends for conversation.

Nets operate more or less formally depending on their purpose and organization. Groups of nets may organize and operate in collaboration for a common purpose, such as to pass along emergency messages in time of disaster. One such system of nets is the National Traffic System (NTS), organized and operated by members of the American Radio Relay League (ARRL) to handle routine and emergency messages on a nationwide and local basis.