Abstract: An adapter for a fishing rod holder for pivoting the butt end of a fishing rod handle into the central portion of a socket assembly forming a portion of the rod holder to facilitate registry of one of a pair of perpendicularly arranged grooves in the butt end of the fishing rod handle with a transverse pin in the bottom end of the socket assembly to preclude rotational movement of the fishing rod about its longitudinal axis when assembled with the fishing rod holder. The adapter is in the form of a sleeve having an internal bore which flares outwardly and upwardly to guide the butt end of a fishing rod handle toward the smaller portion of the bore and centrally in the tubular member forming the socket assembly. In one embodiment of the adapter, the adapter has a continuous periphery and is machined to accurately fit into standard size socket assemblies.