Charles Napier Sturt (28 April 1795 – 16 June 1869) was a British officer and explorer of Australia, and part of the European exploration of Australia. He led several expeditions into the interior of the continent, starting from Sydney and later from Adelaide. His expeditions traced several of the westward-flowing rivers, establishing that they all merged into the Murray River, which flows into the Southern Ocean. He was searching to prove his own passionately held belief that an "inland sea" was located at the centre of the continent. He reached the rank of Captain, served in several appointed posts, and on the Legislative Council.

Born to British parents in the Bengal Presidency, Sturt was educated in England for a time as a child and youth. He was placed in the British Army because his father was not wealthy enough to pay for Cambridge. After assignments in North America, Sturt was assigned to accompany a ship of convicts to Australia in 1827. Finding the place to his liking, he made his life there.

Charles Sturt was born in the Bengal Presidency, the eldest son (of thirteen children) of Thomas Lenox Napier Sturt, a judge under the British East India Company, and his wife. His grandfather was Humphrey Sturt, and his uncle was the MP Charles Sturt. At the age of five, Charles was sent to live with relatives in England to be educated, as was customary for the children of the colonial upper class. After attending a preparatory school, he was sent to Harrow in 1810.

In 1812, Charles went to read with a Mr. Preston near Cambridge, but his father was not wealthy, and had difficulty finding the money to send him to Cambridge University, or to establish him in a profession. An aunt appealed to the Prince Regent and, on 9 September 1813, Sturt was gazetted as an ensign with the 39th (Dorsetshire) Regiment of Foot in the British Army.

Sturt saw action with the Duke of Wellington in the Peninsular War and against the Americans in Canada during the War of 1812. He returned to Europe a few days after the Battle of Waterloo. Sturt was gazetted lieutenant on 7 April 1823 and promoted captain on 15 December 1825. With a detachment from his regiment, Sturt escorted convicts aboard the Mariner to New South Wales, arriving in Sydney on 23 May 1827.

Sturt was a cousin of the wife of Henry Dumaresq, brother-in-law of Governor Ralph Darling, which was later to complicate his relationship with Sir Thomas Mitchell, who resented those whom he judged were treated favourably by Darling.

Sturt found the conditions and climate in New South Wales much better than he expected, and he developed a great interest in the country. The Governor of New South Wales, Sir Ralph Darling, formed a high opinion of Sturt and appointed him major of brigade and military secretary. Sturt became friendly with John Oxley, Allan Cunningham, Hamilton Hume, and other explorers. Sturt was keen to explore the Australian interior, especially its rivers.

Sturt received approval from Governor Darling on 4 November 1828 to explore the area of the Macquarie River in western New South Wales. It was not, however, until 10 November that the party started out. It consisted of Sturt, his servant Joseph Harris, three soldiers and eight convicts; on 27 November Sturt was joined by Hamilton Hume as his first assistant. Hume's experience proved to be very useful. A week was spent at Wellington Valley breaking in oxen and horses, and on 7 December the real start into comparatively little known country was made. 1828–29 was a period of drought and the party had difficulty in finding sufficient water. They had followed the courses of the Macquarie, Bogan and Castlereagh rivers and, though its importance was scarcely sufficiently realised, had visited the Darling River. The party returned to Wellington Valley on 21 April 1829. The expedition proved that northern New South Wales was not an inland sea, but deepened the mystery of where the western-flowing rivers of New South Wales went.