Posse comitatus is the authority of a law officer to conscript any able-bodied males to assist him.
Posse comitatus may also refer to:
Posse Comitatus (organization), a loosely organized far-right social movement that opposes the United States federal government and believes in localism
Posse Comitatus Act, a United States federal law prohibiting members of the military from exercising powers that maintain "law and order" on non-federal property