SLTT stands for state, local, tribal, and territorial governments. In U.S. cybersecurity, it is a standard way to group non-federal public agencies that run essential services such as courts, schools, utilities, public health, emergency response, and local administration.
SLTT organizations matter because they often have limited staff, older systems, and wide exposure to phishing, ransomware, and supply-chain attacks. Defenders use the term when discussing shared guidance, incident response support, grant programs, and security tooling tailored to public-sector constraints. In real attacks, SLTT entities are often targeted for disruption and extortion because downtime can affect large communities. In defense planning, the label helps coordinate baseline controls, logging, patching, identity protection, and recovery across many different governments without treating them as one uniform environment.