Three-way fittings are pipe fittings used for pipe connections. Also known as three-way pipe fittings or three-way connectors, they are used at the point where the main pipe branches off.

A three-way is a type of industrial pipeline 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 outlets, used at junctions where three pipes, either identical or different, converge. The primary function of a three-way is to alter the fluid direction.