James David Graham Niven was born in London, England, the son of William Edward Graham Niven and French/British Henrietta Julia de Gacher, who was born in Wales. He was named David for his birth on St. David's Day. His father died during the Gallipoli Campaign in 1915 and his mother remarried Sir Thomas Comyn-Platt. After attending Stowe as a boy Niven trained at the Royal Military Academy Sandhurst, which gave him the "officer and gentleman" bearing that was to be his trademark. He served for two years in Malta with the Highland Light Infantry. Niven often claimed that he was born in Kirriemuir, Angus, Scotland, which he believed sounded more romantic than London.
Arriving in Hollywood during the early 1930s, he first worked as an extra in westerns, then had a walk-on part in the 1935 version of Mutiny on the Bounty. He then landed a long term contract as a supporting player with independent film producer Samuel Goldwyn
which firmly established his career and allowed him to progress to leading man status in many films such as the RKO comedy Bachelor Mother (1939) with Ginger Rogers
During World War II Niven served in the British army, rising to the rank of lieutenant colonel in the British Commandos and landing at Normandy. He played in two films during the War, both of strong propaganda value: The First of the Few (1942) and The Way Ahead (1944). During his war service, his batman was Pte. Peter Ustinov
Despite the public interest in what celebrities did during the war, Niven remained politely, but definitely, close-mouthed about the subject. After Great Britain declared war in 1939, he was one of the first actors to go back and join the army. Although Niven had a reputation for telling good old stories over and over again, he was totally silent about his war experience. He said once: "I will, however, tell you just one thing about the war, my first story and my last. I was asked by some American friends to search out the grave of their son near Bastogne. I found it where they told me I would, but it was among 27,000 others, and I told myself that here, Niven, were 27,000 reasons why you should keep your mouth shut after the war." He did finally open up about it in his 1971 autobiography, The Moon's A Balloon, however, mentioning his private conversations with Winston Churchill
, the bombings, and what it was like entering a nearly completely destroyed Germany with the occupation forces.
In spite of six years' virtual absence from the screen, he came in second in the 1945 Popularity Poll of British film stars. On his return to Hollywood after the war he was made a Legionnaire of the Order of Merit (the highest American order that can be earned by a foreigner). This was presented to Lt. Col. David Niven by Gen. Dwight D. Eisenhower
He resumed his career after the war with films such as Around the World in Eighty Days (as Phileas Fogg), The Guns of Navarone, The Pink Panther and as Sir James Bond in the unofficial series spoof Casino Royale. He won an Academy Award for his performance in Separate Tables (1958). Late in life, he gained critical acclaim for his memoirs of his boyhood and acting career, The Moon's A Balloon (1971) and Bring On the Empty Horses (1975).
In 1940, Niven married Primula Susan Rollo (1918–1946), the aristocratic daughter of a British pilot, after a whirlwind two-week romance; they had two sons, David Jr. and Jamie. She died at age 28, only six weeks after moving to America, of a fractured skull and brain lacerations after accidentally falling down a flight of stone steps during a hide-and-seek party at the home of Tyrone Power
; she had mistakenly opened a door to a cellar and stepped inside, apparently thinking it was a closet. She died one day later. Niven recalls this as the darkest period of his life, years afterwards thanking his friends for their patience and forebearance during this time.
He eventually rallied and returned to film making.
Niven's second wife, whom he married in 1948, ten days after they met, was Hjordis Paulina Tersmeden (née Genberg, 1921–1997), a divorced Swedish fashion model and frustrated actress. The moment of his meeting her was recounted by Niven in what might be an example of his writing Upon seeing her, he said, his mouth and knees suddenly seemed to be 'full of champagne.'
They had two adopted daughters, Kristin and Fiona, one of whom has long been rumored to be Niven's child by another fashion model, Mona Gunnarson. The marriage was as witheringly tumultuous as Niven's previous marriage had been happy. Thwarted from an acting career, Hjordis Niven began having public affairs with other men and soon became an alcoholic. Bitter, estranged, and plagued by depression, she showed up drunk at Niven's funeral, after having been convinced to attend by family friend Rainier III of Monaco.
Niven died in Switzerland on July 29, 1983 (the same day as his The Prisoner of Zenda and A Matter of Life and Death co-star Raymond Massey) of motor neurone disease (a.k.a. Lou Gehrig's disease) at age 73. He had just completed work on Trail of the Pink Panther and Curse of the Pink Panther. Niven was incomprehensible at one point during the filming of both movies, and his voice was dubbed over in post-production by impressionist Rich Little