William Moorcroft (1767 – 27 August 1825) was an English veterinarian and explorer employed by the East India Company. Moorcroft travelled extensively throughout the Himalayas, Tibet and Central Asia, eventually reaching Bukhara, in present-day Uzbekistan.

Moorcroft was born in Ormskirk, Lancashire, the illegitimate son of Ann Moorcroft, daughter of a local farmer. He was baptised in 1767 in St Peter & St Paul, the Parish Church of Ormskirk, where there is a commemorative plaque to his life. His family had sufficient means to secure an apprenticeship with a surgeon in Liverpool but during this time an unknown disease decimated cattle herds in Lancashire and young William was recruited to treat stricken animals. His proficiency so impressed the county landowners they offered to underwrite his education if he would abandon surgery to attend a veterinarian college in Lyon, France. He arrived in France in the revolutionary year of 1789 and became the first Englishman to qualify as a veterinary surgeon. On completing his course he began practice in London, established a "hospital for horses" on Oxford Street, helped found the first British veterinary college, proposed new surgical methods for curing lameness in horses, and acquired four patents on machines to manufacture horseshoes. In 1795, Moorcroft published a pamphlet of directions for the medical treatment of horses, with special reference to India, and in 1800 a Cursory Account of the Methods of Shoeing Horses.

In 1803 a citizen army was mobilised to defend Britain against a threatened Napoleonic invasion. Moorcroft joined the Westminster Volunteer Cavalry. He came to the attention of Edward Parry, a director of the East India Company (EIC), who recruited Moorcroft to manage the East India Company's stud in Bengal. In 1808 Moorcroft left for India and arrive in Calcutta, the then capital of British India.

Moorcroft found the company stud in dire shape, with apparently depressing signs of laxness, neglect and ignorance. Often undersized mares were bred with local stallions, the best colts were kept back and stud books falsified. He improved the procedures at the stud. He took brisk charge of his staff and weeded out deficient horses. Moorcroft also cultivated oats on a large scale in India and set aside 3,000 acres (12 km²) at Pusa for its production.

In 1811 Moorcroft travelled extensively in the northern sub-continent in search of better breeding stock. Despite travelling to Lucknow, the capital of Oudh, and to Benares, then still part of Maratha territory, Moorcorft failed to acquire the ideal breeding horses that he sought. In Benares he learned that Bukhara was rumoured to have "the greatest horse market in the world." Moorcroft recruited a Persian named Mir Izzat-Allah to make a scouting trip to Bukhara and map out the route. He also learned that fine breeding horses might be found in Tibet.

Moorcroft and Captain William Hearsey disguised themselves as gosain pilgrims, and travelled through Garhwal, carrying a stock of merchandise for trading with the Tibetans. They travelled through the upper Ganges valley, and then the Dhauliganga valley and crossed the Niti Pass on 1 July 1812. Here they were met by Rawats^{[clarification needed]} who were under strict orders from Tibet to repel the foreigners. With his charm, the promise of gain, and proficient use of his medical kit, Moorcroft gained the friendship of two influential Rawats, Deb Singh and his brother Bir Singh. The orders from Tibet were ignored and Amer Singh, the son of Bir Singh, was recruited to serve as a guide through the Niti pass and over the Tibetan plateau. Arriving at the town of Daba they awaited permission to proceed to Gartok (then the seat of the Garpon, or Governor, of Western Tibet). The Garpon agreed to sell them pashm shal wool (Cashmere), and granted permission for them to travel to the sacred lake of Manasarowar. Moorcroft reached the main upper branch of the Indus near its source, and on 5 August arrived at Lake Manasarovar, which they explored extensively. Returning via the Sutlej valley, he was detained for some time by the Gorkhas in Nepal, but eventually reached Calcutta in November, only to be chastised severely by the EIC for his failure to find horses—they were not interested in shawl wool or Tibetan lakes.^{[citation needed]}

The journey to Tibet only served to whet Moorcroft's appetite for more extensive travel. But when he broached the idea of a new horse buying expedition to Bukhara in 1816, a searing reply from the EIC Board of Managers warned Moorcroft to keep "steady" at his stud duties and not "waste his time" on "wild and romantick (sic) excursions to the banks of the Amoo (Oxus) and the plains of Chinese Tartary." What Moorcroft coveted most were the Turkoman horses, with their pale golden coats, narrow chests, long necks and sturdy legs. The "good Turcoman horses" that Marco Polo had described some 500 years earlier could travel 100 miles (160 km) a day for weeks on end. Their descendants, the Akhal-Teke, are bred to this day in Turkmenistan and Russia. Moorcroft persisted in his quest and his seven-year campaign was finally rewarded in May 1819 when Charles Metcalfe, head of the EIC's Political and Secret Department, granted him leave to proceed. Metcalfe's goal was to use his friend as an intelligence scout on his epic journey.

Moorcroft's preparations took nearly a year. His roster of recruits included the Persian, Mir Izzat Khan, who had already made the trip alone some years before and an Afghan, Gulam Hyder Khan from his previous expedition to Tibet. Nineteen-year-old George Trebeck, a recent arrival in Calcutta, was selected as second in command. The total expedition totalled 300 persons, including an escort of 12 Gurkas, sixteen horses and mules along with £4,000 of trading goods as well as medical supplies and equipment.