William Blenkiron (c. 1807 – 25 September 1871) was an English breeder of racehorses. Blenkiron was born in Marrick, Richmond, Yorkshire, about 1807. He was originally brought up as a farmer, but he abandoned that pursuit, and moved to London in 1834, and began business as a general agent in Cheapside. In 1845, he added to his establishment a manufactory of stocks and collars, and three years later retired in favour of his son. He died at Middle Park 25 September 1871, in his sixty-fourth year, and was buried in Eltham churchyard 30 September.