An object of the present invention is to provide an excellent cartilage regeneration-promoting agent that can promote regeneration of cartilage efficiently and is highly safe, and a medicine and a food that utilizes the cartilage regeneration-promoting agent. Thus, the present invention relates to a cartilage regeneration-promoting agent that includes at least one of hydroxytyrosol and a precursor of hydroxytyrosol, and to a medicine and a food that includes the cartilage regeneration-promoting agent.