Grey Momus (1835 – 1856) was a British Thoroughbred racehorse and sire. In a career that lasted from August 1837 to 1839 he competed twenty-one times and won fourteen races. Grey Momus first attracted attention as a two-year-old when he recorded two impressive victories at Goodwood in August. In the following year he won seven times from nine starts, taking two of the year's biggest races, the 2000 Guineas at Newmarket and the Gold Cup at Ascot.