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

A three-way 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 pipe ends, used at junctions where three pipes, either the same or different, converge. The primary function of a three-way is to alter the direction of the fluid flow.