Raced from 1752, winning many races - lost to Jason in the King's Plate at Newmarket in 1755, but won the following year, was also narrowly beaten by Spectator for the Jockey Club Plate at Newmarket in 1756, and was sold soon after to the Marquess of Rockingham. He famously won a four-mile race at York in August 1759 against a strong field. He was beaten only four times in his racing career, but was notoriously temperamental and difficult to manage.
Whistlejacket retired to the Rockingham stud at Wentworth Wodehouse, near Rotherham in south Yorkshire, where he got a fair number of runners.
George Stubbs painted the life-size portrait of Whistlejacket at Wentworth. He was described as a `yellow-sorrel horse with white mane and tail`.