There is provided an electric actuator in which a speed reduction mechanism and an output portion are disposed adjacent to each other in a radial direction in an opening portion of a housing main body, a cover member has a speed reduction mechanism cover which faces and surrounds the speed reduction mechanism, an output portion cover which faces and surrounds the output portion, and a constricted portion which connects the speed reduction mechanism cover and the output portion cover, the cover member is fixed to the housing main body by a plurality of caulking portions provided on a side wall portion, and, between two adjacent caulking portions interposing the constricted portion therebetween, one of the two caulking portions of the speed reduction mechanism cover is fixed toward a central axis of the speed reduction mechanism, and the other is fixed toward a central axis of the output portion.