Rotary joint may refer to:
Coupling, a mechanical device used to connect two shafts together at their ends for the purpose of transmitting power, including flexible couplings Rotary union, a coupling for passing fluid through a rotating joint Pivot joint, between animal bones Slip ring assembly, used to send electrical power and signals across a rotating connection Waveguide rotary joint, used to send microwave power and signals across a rotating connection , in the International Space Station