The 2021 World's Best Racehorse Rankings, sponsored by Longines was the 2021 edition of the World's Best Racehorse Rankings.[1] It was an assessment of Thoroughbred racehorses issued by the International Federation of Horseracing Authorities (IFHA) on 25 January 2022.[2] It included horses aged three or older which competed in flat races during 2021. It was open to all horses irrespective of where they raced or where they were trained.