David Urquhart (1805 - May 16, 1877) was a British diplomat and writer.

Born Cromarty, Scotland, Urquhart was educated, under the supervision of his widowed mother, in France, Switzerland, and Spain. He returned to Britain in 1821 and spent a gap year learning farming and working at the Woolwich Arsenal before attending St John's College, Cambridge. He never completed his classics degree as his mother's finances failed.

In 1827, Urquhart joined the nationalist cause in the Greek War of Independence. Seriously injured, he spent the next few years championing the Greek cause in letters to the British government, a self-promotion that entailed his appointment in 1831 to Sir Stratford Canning's mission to Constantinople to settle the border between Greece and Turkey.

Urquhart's principle role was to nurture the support of Reschid Pasha , intimate advisor to the Sultan Mahmud II. He found himself increasingly attracted towards Turkish civilisation and culture, becoming alarmed at the threat of Russian intervention in the region. Urquhart's campaigning, including publication of Turkey and its Resources, culminated in his appointment on a trade mission to the region in 1833. He struck such an intimate relationship with the government in Constantinople that he became outspoken in his calls for British intervention on behalf of the Sultan against Muhammad Ali of Egypt in opposition to the policy of Canning. He was recalled by Palmerston just as he published his violently anti-Russian pamphlet England, France, Russia and Turkey which brought him into conflict with Richard Cobden.

In 1835 he was appointed secretary of embassy at Constantinople, but an unfortunate attempt to counteract Russian aggressive designs in Circassia, which threatened to lead to an international crisis, again led to his recall in 1837. In 1835, before leaving for the East, he founded a periodical called the Portfolio, and in the first issue printed a series of Russian state papers, which made a profound impression. From 1847 to 1852 he sat in parliament as member for Stafford, and carried on a vigorous campaign against Lord Palmerston's foreign policy.

The action of England in the Crimean War provoked indignant protests from Urquhart, who contended that Turkey was in a position to fight her own battles without the assistance of other powers. To attack the government, he organized "foreign affairs committees" which became known as Urquhartite, throughout the country, and in 1855 founded the Free Press (in 1866 renamed the Diplomatic Review), which numbered among its contributors the socialist Karl Marx. In 1860 he published his book on Lebanon. From 1864 until his death, Urquhart's health compelled him to live on the continent, where he devoted his energies to promoting the study of international law.

He married Harriet Angelina Fortescue and the couple had three sons, one of whom, William, died aged only thirteen months, and two daughters. She wrote numerous articles in the Diplomatic Review under the signature of Caritas.

Urquhart introduced Turkish baths into Great Britain. He advocated their use in his book Pillars of Hercules (1850), which attracted the attention of the Irish physician Richard Barter. Baxter introduced them in his system of hydropathy at Blarney, County Cork. The Turkish baths in Jermyn Street, London were built under Urquhart's direction.