The replaceable bearing for a conveyor roller is installed in a bearing housing, which is removably installed within the end of the conveyor roller. The bearing housing threads into a mating insert or sleeve, which is permanently installed within the end of the conveyor roller. Alternatively, the inside of the conveyor roller may be threaded and the bearing housing threaded directly into the conveyor roller, if roller wall thickness is sufficient. The outer face of the housing includes a plurality of notches so that a mating wrench engages the notches to thread the housing and its bearing into or out of the end of the roller. The replaceable bearing allows the bearing and its housing to be replaced while retaining the conveyor roller.