An occurrence of thermal distortion when heterogenous materials are joined together is suppressed. Provided is a joining structure that includes a first member, a second member, a rivet and a resin-filled portion. The first member is formed of a first material. The second member is formed of a second material that is different from the first material. The rivet penetrates through at least the first member and joins the first member and second member together. The resin-filled portion is provided around the rivet at a side of the first member at which the second member is disposed. The resin-filled portion is formed by at least one of the first member and the second member and forms a gap between the first member and the second member. A resin member is disposed inside the resin-filled portion.