William Mansfield, 1st Baron Sandhurst

General William Rose Mansfield, 1st Baron Sandhurst, GCB, GCSI, DCL (21 June, 1819-23 June, 1876), was a British military commander who served as Commander-in-Chief of India from 1865 to 1870.

Mansfield was the fifth of the seven sons of John Mansfield of Diggeswell House in Hertfordshire, and his wife, daughter of General Samuel Smith of Baltimore in the United States. His grandfather was the prominent lawyer Sir James Mansfield, Solicitor General from 1780 to 1782 and in 1783 and Chief Justice of the Common Pleas from 1804 to 1814.

Mansfield was educated at Royal Military College, Sandhurst and was commissioned into the 53rd Foot in 1835 and remained in that regiment throughout his career. He was mostly active in India and served in the Sutlej campaign of 1845 to 1846, commanded the 53rd Regiment in the Punjab from 1848 to 1849 and was employed in the Peshawar operations in 1851 and 1852.

In 1855, during the Crimean War, Mansfield was appointed military adviser to the Ambassador at Constantinople Lord Stratford de Redcliff, and accompanied him to the Crimea. He then returned to India and served as Chief-of-Staff during the Indian Mutiny campaign from 1857 to 1859 and as Commander-in-Chief in India from 1865 to 1870. Mansfield was then Commander of the Forces in Ireland from 1870 to 1875.

In 1871 he was admitted to the Irish Privy Council and raised to the peerage as Baron Sandhurst, of Sandhurst in the County of Berkshire. Lord Sandhurst died in June 1876, aged 57. He was succeeded in the Barony by his eldest son William, who was created Viscount Sandhurst in 1917. However, this title became extinct on his death while he was succeeded in the Barony by his younger brother.