Three-way fittings are used for pipe fittings and pipe connections. Also known as three-way pipe fittings, three-way connectors, they are used at the point 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 shapes, with both equal and unequal diameter openings, used at junctions where three identical or different pipelines converge. The primary function of a three-way fitting is to alter the direction of fluid flow.