Child actress, businesswoman and diplomat.

Born April 23, 1928; Died February 10, 2014.

Shirley Temple, who has died at the age of 85, is nonetheless certain to be fixed indelibly in the public mind as a child; indeed, as the epitome of the child star.

She was signed to her first movie studio at three, and officially retired from films aged 22, though almost all her most successful pictures were made by the time she was 10. Before her seventh birthday, she had won an Oscar, had her hand and footprints set in concrete outside Grauman's Chinese Theatre, and was pulling in well over $150,000 a year; between 1935 and 1939, she was the leading Hollywood box office draw for four years in a row. She was painted by Salvador Dalí, in the guise of a sphinx surrounded by human bones and a vampire bat, and lent her name and image to everything from cereal to crockery and clothing to cosmetics. Shirley Temple dolls alone generated $45 million worth of sales before the war.

Given the extraordinary fame she achieved in the 1930s, everything after the age of 12 was bound to look a little anticlimactic. But Shirley Temple Black, as she became after her second marriage in 1950, maintained a degree of prominence and a list of achievements which were remarkable when measured against anything other than her life as a child star.

She made a return to acting with a number of moderately successful television appearances from the late 1950s onwards; became active in the Republican Party, standing (unsuccessfully) for Congress in California; served, successively, as US Representative to the United Nations, as ambassador to Ghana, as Chief of Protocol and then as ambassador to Czechoslovakia; she was on the boards of numerous corporations, including the Walt Disney Company and the Bank of America; she was an early and prominent campaigner against breast cancer, from which she recovered in the early 1970s.

Shirley Temple was born on April 23 1928 in Santa Monica, California, the third child of George Temple, a banker, and his wife Gertrude. Her mother encouraged her enthusiasm for singing and dancing, and enrolled her at Mrs Meglin's Dance Studio when she was three.

There she was spotted by Jack Hays and Charles Lamont, producers of short films featuring children in parodies of mainstream pictures. Shirley Temple appeared in eight films for Educational Pictures, for $10 a day, with a sideline in advertisements for breakfast cereal, and was also lent out by the studio for Red-Haired Alibi (1932), her first full feature film.

After Educational Pictures went bust, Shirley Temple signed to Fox Films in 1934, taking a number of bit parts in their films, and on loan to Paramount, Warner Bros and Universal. Her father was her agent, and her mother (on $150 a week) her make-up artist and chaperone.

Her first big success came in Stand Up and Cheer! which was not only designed to lift spirits during the Great Depression, but took the effort to do so as the subject of its plot. At the end of 1934, Fox released Bright Eyes, which had been written to showcase her talents, and featured her best-known song, On the Good Ship Lollipop. The sheet music sold half a million copies.

It set the pattern for her pictures, which tended to concentrate on her childish optimism setting an example for poor, cynical or down-trodden adults. It was a winning formula, and films in 1935, such as The Little Colonel, Our Little Girl and Curly Top (which featured Animal Crackers in my Soup), won her admiration from President Franklin D Roosevelt, who enlisted her as a weapon against the Depression, declaring: "as long as our country has Shirley Temple, we will be all right".

She made four films again in 1936, including Dimples and Poor Little Rich Girl and in 1937 had perhaps her most successful outings in Wee Willie Winkie and Heidi. The former led to a celebrated libel suit after the novelist Graham Greene accused her of "dubious coquetry" and "dimpled depravity" in the magazine Night and Day.

Greene lost (the damages were £3500), and decamped to Mexico, leading indirectly to his novel The Power and the Glory. In 1938, she appeared in Rebecca of Sunnybrook Farm, Little Miss Broadway and Just Around the Corner, which all did well and then, in 1939, The Little Princess, her first Technicolor picture, which was a critical and commercial success.

But it was also to be the high watermark of her career, as Darryl Zanuck, convinced she could move from child star to an adult career, refused to lend her to MGM for The Wizard of Oz and instead cast her in Twentieth Century Fox's Susannah of the Mounties, her last real commercial success, and The Blue Bird (1940), her first real flop.

She had modest appearances through her teens, though her parents had bought out her contract and sent her to school when she was 12. She was effective in Since You Went Away (1944), The Bachelor and the Bobby-Soxer opposite Cary Grant (1947), and with Henry Fonda in Fort Apache, which also featured her first husband, John Agar, whom she married in 1945, and with whom she had a daughter. Her favourite role was in That Hagen Girl (1947, with her friend Ronald Reagan).

After the end of her film career, she found that, of the $3.2 million she had earned, only $45,000 was left. Her first marriage ended in 1949, and after her divorce was finalised Shirley Temple married Charles Alden Black, a businessman with a pineapple company, who later moved into salmon farming. They remained married until his death in 2005, and had a son and a daughter.

Despite her television appearances in the 1950s and early 1960s, by the end of that decade she decided to devote herself to public service, becoming, under Gerald Ford's presidency, ambassador to Ghana from 1974 to 1976, and then Chief of Protocol, in which capacity she organised Jimmy Carter's inauguration. President Reagan appointed her to the state department as a foreign affairs officer and George HW Bush made her ambassador to Czechoslovakia (1989-1992).

Shirley Temple once declared: "When I was 14, I was the oldest I ever was. I've been getting younger ever since." She is survived by her three children.