Bloody Buttocks was a British Thoroughbred sire who was the leading sire in Great Britain and Ireland in 1739. He was owned by John Crofts.

Bloody Buttocks was a grey Arabian horse bred by Mr. Crofts, but his pedigree was never published.^[1] The horse found his unusual name from a red mark on his hip.^[2]

Bloody Buttocks was a successful stallion for Crofts at Barforth in Yorkshire.^[1][3] He was leading sire in Great Britain and Ireland in 1739 and sired many good runners and broodmares, including:

• Louse – a grey horse foaled in 1726, his dam by Greyhound. He won two races at Newmarket and the Royal Plate at Salisbury.^[1]
• Grey Brocklesby – a grey mare foaled in 1728 out of Brocklesby^[4] She was the dam of Little John who won many King's Plates.^[1][4] Her daughter Caelia was the granddam of Gimcrack^[5]
• Bay Bloody Buttocks – a bay mare foaled in 1729 out of a daughter of Greyhound^[4] She was the dam of King's Plate winner Spinster.^[1]
• Whitefoot – a chestnut horse foaled in 1729. He won the Royal Plates at Edinburgh and Newmarket. He sired Sportsman, who won many King's Plates.^[1]
• Flintshire Lady – a bay mare foaled in 1731, dam by Jigg.^[4] She was the dam of Jenny Jessamy.^[1]
• Careless – also known as Hazard, a chestnut horse foaled in 1733, his dam by Greyhound. He won several races from 1738 to 1745.^[1]
• Dairymaid – also known as Grey Bloody Buttocks, a grey mare foaled in 1733, she was a full-sister to Bay Bloody Buttocks.^[4] She was the dam of Squirrel, who won the inaugural 1400 Guineas Stakes in 1758.^[1] Squirrel was also the damsire of Derby winner Noble.^[6]
• Dairymaid – a bay mare foaled in 1737 out of Bay Brocklesby.^[4] She was the dam of Prince T'Quassaw.^[1]
• Madam – a grey mare foaled in 1737, her dam by Cade. She won her only two races, one at Bishop Auckland and one at Durham, and was the dam of Twig.^[1]

He also sired Rainbow^[7] and was the damsire of Belmont, who was beaten only twice.^[1]