Spilletta (1749 – 1776) was a British Thoroughbred racehorse. She only raced once and is best known for being the dam of the undefeated Eclipse.

Spilletta was a bay filly bred by the Sir Robert Eden and foaled in 1749. She was sired by the undefeated Regulus.^[1] Regulus was also a very successful stallion, becoming Champion sire eight times. Regulus also sired Careless and Cato.^[2] Spilletta's dam was Mother Western, a daughter of Smith's son of Snake.^[1]

Spilletta only started one race, in April 1754 at Newmarket for a £50 Plate. She lost the race to Sir Charles Sedley's Royal, the Marquess of Hartington's Tantivy and Mr. Curzon's Jason.^[3]

Spilletta was a broodmare at the Duke of Cumberland stud. She produced five foals:

• Ariaden – a bay filly foaled in 1759 and sire by Crab.^[1]
• Eclipse – a chestnut stallion foaled in 1764 and sired by Marske.^[1] He was undefeated during his 18 race career and is generally considered one of the best horses ever. His wins included 11 King's Plates, the Great Subscription Purse and a match against Bucephalus.^[3] He sired Planet, Pot-8-Os, King Fergus, Mercury, Young Eclipse, Saltram, Serjeant and Annette.^[4] Eclipse is the sire-line ancestor of most Thoroughbreds alive today.
• Proserpine – a bay mare foaled in 1766 and sired by Marske.^[1] She never raced, but was the dam of Humbug and six others.^[5]
• Garrick – first called Hyperion, a chestnut stallion foaled in 1772 and sired by Marske.^[1] He won a 140 guineas race at Newmarket in 1777. As a stallion he stood at Newmarket and near Malton in Yorkshire.^[3]
• Briseis – a chestnut filly foaled in 1774 and sired by Chrysolite.^[1]

Spilletta died in 1776.^[1]

Note: b. = Bay, br. = Brown

* Spilletta is inbred 4S × 3D to the stallion Snake, meaning that he appears fourth generation on the sire side of his pedigree and third generation on the dam side of his pedigree.