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

A three-way fitting is a type of industrial pipe fitting 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 openings, and is used at junctions where three pipes, either identical or different, converge. The primary function of a three-way fitting is to alter the flow direction.