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

A three-way is a type of piping fitting with three outlets, consisting of 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 identical or different pipelines converge. The primary function of a three-way is to alter the fluid direction.