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

A three-way fitting is a type of pipeline component with one inlet and two outlets; or two inlets and one outlet. It comes in T and Y configurations, with both equal and unequal diameter outlets, and is used at junctions where three pipes of the same or different sizes converge. The primary function of a three-way fitting is to alter the flow direction.