An "Anthony Eden" hat, or simply an "Anthony Eden", was a type of headgear popularised in Britain in the mid-20th century by politician Anthony Eden. Eden, who was known for his sartorial elegance, favoured a silk-brimmed, black felt homburg at a time when most Britons preferred the trilby or the bowler. Eden held a number of cabinet posts in the 1930s and the 1940s, and was Prime Minister from 1955 to 1957.

The hat became so associated with him that it was commonly known in the UK as the "Anthony Eden" (or, in London's Savile Row, simply as the "Eden"). It was not marketed as such and the name was purely informal, but the use of the term was widespread, entering dictionaries and phrase books: for example, it was still listed in the 17th edition of Brewer in 2005 and as recently as 2010 the fashion "guru" Trinny Woodall cited the hat as an example of Eden's reputation for being well dressed. It came into particular vogue among civil servants and diplomats in Whitehall and, to that extent, rather belied the stereotypical view, that lasted until well after the Second World War, of civil servants as a "bowler hat" brigade.

The homburg had initially been popularised in Britain by King Edward VII who often visited Bad Homburg in Germany. It was essentially a more rigid variant of the trilby which had been fashionable since George du Maurier's novel of that name was published in 1894. The writer and broadcaster Rene Cutforth recalled in the 1970s that:

one of things that strikes me most about the Thirties scene when I think about it now is the trilby hat, the universal headgear of the middle classes ... Sometime early in the century, it must have been a wild gesture of freedom and informality ... By the Thirties it had certainly become degenerate ... It was a hat which had lost all aspiration: it had become a mingy hat ... .

In such circumstances Eden's adherence to the homburg seemed fresh and dashing. He is one of only two British Prime Ministers to have had an item of clothing named after him, the other being the Duke of Wellington (his boot).

Eden became, at 38, the youngest Foreign Secretary since William Pitt the Younger in the late 18th century. As a relatively youthful politician among mostly much older men, he appeared fashionably dressed, even flamboyant. In 1936 the American magazine Time referred to his "pin-stripe trousers, modish short jacket and swank black felt hat", worn during a diplomatic mission to the League of Nations in Geneva. Many remarked too on Eden's "film star" appeal, even as late as the 1950s when, as Prime Minister, he retained his youthful good looks. His biographer D. R. Thorpe, who likened the young Eden to a mixture of Sir Galahad (Eden won the Military Cross in the First World War) and Beau Brummel (the Regency dandy in whose London house Eden lived for a time), commented on a photograph of him, arriving in Russia by train in hat and fur-lined coat in 1935, that "it seemed to some as if Tolstoy's Count Vronsky [a glamorous character in the novel Anna Karenina] were alighting at the platform".

In addition to the homburg, Eden was associated with the mid-1930s fashion for wearing a white linen waistcoat with a lounge suit, while the poet and novelist Robert Graves likened Eden's moustache to those of film stars Ronald Colman, William Powell and Clark Gable: "the new moustache was small, short and carefully cut, sometimes slightly curved over the lip at either end, sometimes making a thin straight line". When Eden visited New York City in 1938 he was "deluged with fan mail from teenage college girls to elderly matrons", while women reporters and society editors "gushed about his classic features, his long dark eyelashes, his limpid eyes, his clear skin, his wavy hair, his charm and magnetism". In another American city, a display of homburgs in a shop window was adorned with the sign "Welcome to Anthony Eden". In Amsterdam the hat became known as the "Lord Eden".

The journalist Malcolm Muggeridge, who was not an admirer of Eden, recalled that, among other qualities, "an elegant appearance and an earnest disposition ... equipped him for dazzling advancement ... An astrakhan collar became him. What came to be known as an Anthony Eden hat grew on heads like his". In June 1938, four months after Eden's resignation from Neville Chamberlain's Cabinet, the Member of Parliament and diarist "Chips" Channon noted that he had "doffed his bowler" to Chamberlain in St. James's Park and that "everyone wears a bowler now ... [Si]nce the Eden debacle black homburgs are "out"". However, in August of that year, the British Minister in Prague, Basil Newton, wore "a black homburg of the kind made fashionable by Anthony Eden" to greet Lord Runciman on his arrival by train at Wilson station for talks with the Czechoslovak government. In 1939, writing to a former classmate during a European tour, the future United States President John F. Kennedy remarked that he had not been doing much work, "but have been sporting around in my morning coat, my 'Anthony Eden' black homburg and white gardenia".