Abstract: A lockable wheel coupling comprises an axle plate having a splined shaft with a central bore, a wheel having a fluted axial bore, and a generally cylindrical locking member. The wheel can be mounted on the axle plate by engaging the shaft thereon with the axial bore of the wheel. Spring biased and radially displaceable retaining lugs within the central bore are engaged with retaining recesses on the inner periphery of the axial bore via aligned apertures in the shaft upon insertion of the locking member into the central bore, to releasably secure the wheel to the axle plate. The locking member carries a cam surface for displacing the retaining lugs outwards into corresponding retaining recesses and a set of locking bolts that snap engage into an annular locking recess in the inner periphery of the central bore to retain the locking member therein. A key operated lock cylinder within the locking member retracts the bolts when rotated so that the member can be removed from the central bore.