An adjustable cable tray joint is provided. The joint has first and second tray receptacles, each having a web and opposing walls. The first tray receptacle may further include joint flanges extending from its walls. The first and second tray receptacles are attached together by pivotal connection, the receptacles defining a rotation relative to each other about the pivotal connection. The joint flanges of the first tray receptacle are disposed proximate to the corresponding walls of the second tray receptacle. The joint includes a locking member extending through a wall of the first tray receptacle and the corresponding wall of the second tray receptacle, the locking member configured to selectively fix and release the rotation between the two tray receptacles.