A rail brace assembly for buttressing the head of a rail resting on the top surface of a brace plate by engaging fishing surfaces formed on the head and base of the rail. The assembly includes a rail brace having an upper slanted surface for engaging the head fishing surface, a lower surface for engaging the base fishing surface, a bottom surface adapted to rest upon the brace plate, a front surface for receiving one leg of a resilient fastener and a pair of laterally extending ears. The assembly further includes a shoulder having laterally extending side surfaces and an opening for receiving another leg of the resilient fastener. The ears of the rail brace overlie the laterally extending side surfaces of the support to prevent longitudinal movement of the rail brace. A resilient fastener having one leg adapted to engage the rail brace surface and another leg adapted to be inserted into the shoulder opening acts to apply a vertical downwardly directed force biasing the brace against the brace plate and and a horizontal inwardly directed force biasing the brace against the rail to thereby prevent lateral and rotational movement of the rail brace.