A vehicle lighting unit ensures support rigidity of a substrate connection part in the front-rear direction without increasing components. The vehicle lighting unit includes a light source part, a power feeding member, a heat dissipation member, and a socket. The light source part has a light-emitting element, and a substrate connected to the light-emitting element. The power feeding member supplies power to the light source part. The heat dissipation member is mounted with the light source part. The socket is assembled on the rear side opposite to the front surface of the heat dissipation member mounted with the light source part. In the vehicle lighting unit, the substrate and the power feeding member are electrically connected by the substrate connection part. The heat dissipation member integrally has an extension support unit that supports at least the substrate connection part in placement in a front-rear direction of the heat dissipation member.