The Sunday Times is a British broadsheet newspaper founded in London in 1822 by Henry White.

It had previously operated as the New Observer between February and April 1821, and then as the Independent Observer until October 1822.

White sold the title to Daniel Whittle Harvey in January 1823. Under its new owner, it was an innovative newspaper, printing the largest illustration in a British newspaper in 1838 with a woodblock engraving showing the coronation of Queen Victoria. It was also one of the first newspapers to serialise a novel.

Alice Anne Cornwell bought the business in 1887 as a gift for the man she later married, Frederick Stannard Robinson, who became the paper's editor. Cornwell sold the title on to Frederick Beer, owner of The Observer, who appointed his wife Rachel as the editor. Rachel Sassoon Beer had been the first woman editor of a newspaper at The Observer.

The brothers William and Gomer Berry, later Lord Camrose and Viscount Kemsley respectively, bought the business in 1903. In 1943, The Sunday Times became the flagship title of the recently established Kemsley Group, the largest newspaper group in Britain at the time. In 1958, it became the first newspaper to publish a separate regular section, the Review section.

Lord Thomson bought the Kemsley Group, and with it The Sunday Times, in 1959. The following year, circulation of The Sunday Times reached one million. In 1962, The Sunday Times launched a separate colour section, the first example of a newspaper magazine supplement, which became known as The Sunday Times Magazine in 1964.

Lord Thomson bought the separate newspaper title The Times in 1966, forming Times Newspapers Limited, bringing the two titles under the same ownership for the first time.

Between 1967 and 1984, under its editor Harold Evans, The Sunday Times was a leading campaigning and investigating newspaper. It reported on the effects of Thalidomide and contributed to the drug being withdrawn.

Following a period of industrial action, in response to attempts by Times Newspapers Limited to modernise production technology, the head of the company decided to sell. Harold Evans attempted a management buy out of The Sunday Times, but the title was sold with the rest of the company to Rupert Murdoch's News International Group in 1981. Harold Evans became editor of The Times and was succeeded by Frank Giles at The Sunday Times.

In 1983, Andrew Neil became the editor of The Sunday Times, taking the newspaper in a more right wing direction, supporting the then Prime Minister Margaret Thatcher. Under Neil's editorship, The Sunday Times ran a number of controversial campaigning stories, including a rejection of the scientific consensus that HIV caused AIDS. Its reputation as a campaigning and investigative newspaper improved under the editorship of John Witherow, from 1994 to 2013. Between 2001 and 2005, the newspaper was politically aligned with the New Labour government of Prime Minister Tony Blair.

The Sunday Times launched its online presence in May 2010, followed by app versions in December 2010. In 2011, The Sunday Times became implicated in the 'phone hacking' scandal centred on another News International title, The News of the World, through its employment of an investigator who impersonated Prime Minister Gordon Brown to obtain financial information.

Martin Ivens became acting editor in 2013, and was succeeded by Emma Tucker in 2020.