A shaft coupling structure includes a shaft, a sleeve, into which the shaft is inserted, and a tolerance ring. The tolerance ring includes a cylindrical main body and a plurality of protuberances, which protrudes outward in a radial direction from an inner circumferential surface of the main body. The tolerance ring is fitted between an outer circumferential surface of the shaft and an inner circumferential surface of the sleeve. A communication passage that connects an inside and an outside of each protuberance is provided between the outer circumferential surface of the shaft and the main body.