Lemberg (1907–1928) was a British Thoroughbred racehorse and sire. He won seventeen times in a career that lasted from 1909 until 1911, taking major races at two, three and four years of age. Lemberg won his most important victory as a three-year-old in 1910 when he won The Derby. His career was marked by his rivalries, first with the fast and precocious Neil Gow and later with the outstanding middle-distance runner Swynford. Lemberg went on to have a successful career at stud.

Lemberg was bred by his owner Alfred W. Cox who raced his horses under the name of "Mr. Fairie". He was sired by Cyllene, an Ascot Gold Cup winner, who went on to become a highly successful stallion. In addition to Lemberg, he sired three other winners of The Derby and through his grandson, Phalaris, he is the direct male-line ancestor of most modern thoroughbreds. Lemberg's dam, Galicia was an outstanding broodmare. In the year before Lemberg's birth she produced Bayardo, the best British horse of his era, and later produced Kwang-Su, who finished second in the Derby.

Lemberg was one of sixteen Classic winners trained by Alec Taylor, Jr. at Manton in Wiltshire.

Lemberg was one of the two best British two-year-old of his generation. After running impressively in a private trial he was sent to Royal Ascot where he started favourite for the New Stakes and won by one and a half lengths. Lemberg followed with odds-on victories the Chesterfield Stakes at Newmarket and the Rous memorial Stakes at Goodwood before being sent to Doncaster for the Champagne Stakes in September. He again started odds-on but finished third of the four runners behind Neil Gow.

He returned to his best form in autumn at Newmarket, winning another Rous Memorial Stakes over five furlongs by a neck from the filly Yellow Slave, to whom he was giving seven pounds. At the same course he then took the Middle Park Stakes giving three pounds to the future American champion Whisk Broom and winning by a neck. At the same course two weeks later he again defeated Whisk Broom, this time by five lengths, in the Dewhurst Stakes, and went into the winter break as favourite for the following season's classics.

Before the season began, there was much speculation concerning the riding plans of the jockey Danny Maher. According to reports in the Telegraph he was offered £3,000 to partner Lemberg, with a rival offer of £5,000 if he was successful in the Derby on Neil Gow. He eventually decided to ride Neil Gow, although he rode Lemberg in later races.

Lemberg began his three-year-old season by running in the 2000 Guineas. He started 7/2 second favourite and was beaten a short-head by Neil Gow in a "superlative" driving finish. Although he been beaten by Neil Gow on both their meetings, Lemberg looked to be the better potential stayer, and was the more fancied for the Derby. At Epsom he started 7/4 favourite in front of a crowd estimated at 250,000, many dressed in black as a mark of respect to the recently deceased King Edward VII. Ridden by Bernard Dillon he tracked the leader, Greenback, throughout the race before taking the lead in the closing stages and winning by a neck in a race record time of 2:35.2. Neil Gow became agitated and gave trouble at the start before finishing fourth. Among the unplaced horses was Lord Derby's Swynford, making his first start of the year.

Lemberg beat a supposedly "moderate lot" by three lengths to win the St James's Palace Stakes at Royal Ascot, with Swynford, among the beaten horses. Lemberg then started favourite for the Grand Prix de Paris at Longchamp. He led the field into the straight before tiring on the heavy ground and finishing fourth to Nuage. At Sandown in July he faced Neil Gow in a much anticipated race for the Eclipse Stakes, then the most valuable race in England with a prize of £10,000. The two colts dominated the race and contested the finish "tooth and nail" before finishing in a dead-heat.