A split cage for a rolling bearing includes a plurality of cage segments formed of synthetic resin and arranged annularly in a circumferential direction. Each cage segment includes: a first rim portion and a second rim portion that are spaced from each other by a predetermined interval and face each other; and a plurality of bar portions extending from the first rim portion to the second rim portion. Spaces, each of which is surrounded by the bar portions adjacent to each other and the first and second rim portions, are formed as pockets that house rolling elements. Projections for reinforcement are formed at radial end portions of boundaries between the bar portions and the first rim portion and/or boundaries between the bar portions and the second rim portion.