Sir Martin (1906–1930) was a Thoroughbred racehorse that was foaled in 1906 in Lexington, Kentucky at Hamburg Place, the stud farm of noted turfman and horse trainer John E.

Sir Martin was the betting favorite for the 1909 Epsom Derby, but stumbled and threw his jockey at the Tattenham Corner turn, allowing King Edward VII's horse Minoru to win.

[4] Sir Martin found early success overseas during his three-year-old season, winning the Wednesday Welter Handicap held at Newmarket in May 1909 shortly after arriving in Britain.

[2] The Americans may have been upset at Sir Martin's defeat, but the ecstatic British crowd soon stormed the track to celebrate the victory of Minoru, the first horse owned by a reigning monarch to win the Epsom Derby.

Sir Martin followed the Epsom Derby failure with an unplaced finish in the Royal Hunt Cup at Ascot and a second in the Grand Prix de Deauville in France.

[1] Sir Martin was retired from racing in 1913 and his first season as a breeding stallion in the U.K., with Winans retaining ownership, was in 1914 when his services were advertised for the Lordship Stud.

[1] Sir Martin was not considered a good sire in England, but his recent status as a "half-breed" in the British stud book thwarted his chances of breeding with quality mares.

The 1914 passage of the Jersey Act was intended to prevent horses with suspect bloodlines (Thoroughbred crosses) from being entered into the British General Stud Book.

[1] While Sir Martin's male line came from certifiable British stock, his female lineage traced to Lexington through his damsire Hanover, thereby excluding him from choice matches.