Assemblies for releasably connecting a golf club head and shaft may include: (a) a shaft engaging member including a rotation-inhibiting structure having a circular cross-section and a first set of circumferentially spaced teeth; (b) a club head engaging member including a retaining structure for engaging the rotation-inhibiting structure, the retaining structure having a circular opening with a second set of circumferentially spaced teeth to engage the first set of teeth on the rotation-inhibiting structure; and (c) a securing system for releasably securing the shaft engaging member with respect to the club head engaging member. The first set of teeth may have a different number of teeth than the second set of teeth. Golf club heads are releasably engaged with shafts so that the shafts can be readily interchanged and/or so that the shaft position with respect to the club head can be readily changed.