Three-way fittings are pipe fittings for connecting pipes. Also known as three-way pipe fittings, three-way connectors, they are used where the main pipe needs to branch off.

A three-way fitting is a type of piping component with three openings: one inlet and two outlets, or two inlets and one outlet. It comes in T and Y configurations, with both equal and unequal diameter outlets, and is used at junctions where three identical or different pipelines converge. The primary function of a three-way fitting is to alter the fluid direction.