Abstract: A swivel cementing head with manifold assembly. The assembly comprises a body connectable to a tool string, and a cementing manifold connectable to the cement source. The manifold is rotatably mounted on the body to provide continuous fluid communication between the manifold and body even when the body is rotating with respect to the manifold. The rotatable connection is provided by a mandrel extending from the body and the sleeve connected to the manifold. The mandrel defines a mandrel central opening therethrough and a transverse mandrel hole in communication with the mandrel opening, and the sleeve defines a transverse sleeve hole therethrough. The mandrel has a mandrel groove and an outwardly facing surface thereof adjacent to the mandrel hole, and the sleeve has a sleeve groove in an inwardly facing surface thereof adjacent to the sleeve hole.