Anne Seagrim was born near Dieppe in France on May 2 1914, the daughter of Cyril Seagrim, the former Inspector General of Police at Indore State, India and his second wife, Kathleen. The Seagrims had moved to Normandy following Cyril Seagrim's retirement, in order to try farming in Normandy, but found it difficult to make farming pay, so in 1923 moved to a smaller house nearer Dieppe, where Anne attended the Collège de Jeunes Filles.

When she was 16 Anne moved to London to attend secretarial college. Following this, she worked initially as a secretary at ICI, 1934-38, then briefly as secretary to Lord Hardwicke, before joining Sir Alan Cobham's company Flight Refuelling, which tested ways of refuelling aircraft in flight, and during the Second World War, researched radar installations on fighter planes. Seagrim was private secretary to the Chief Engineer, Marcus Langley, 1938-44.

In 1944 Seagrim moved to work for the English Electric Company as private secretary to the Chief Engineer and also to the Director of Technical Personnel, C P Snow, helping to set up the company's personnel department. Seagrim formed a close working and personal relationship with Snow, reading and typing up the manuscripts of his novels, helping in the writing of Snow's own book reviews, and remaining close to him until Snow’s death in 1980.

In March 1950 Seagrim left the English Electric Company to work as secretary to the Duke of Windsor in Paris. Initially, her main job was to work on the Duke's memoirs, "A King’s Story", which were published in 1951, but she remained with the Windsors until 1954, travelling with them regularly between France and New York [United States], dealing with literary, business and social affairs, travel and the press. She was also responsible for the supervision of reconstruction, decoration and furnishing of the Windsors' two houses in France.

Seagrim then joined the Northern Aluminium Company, part of Alcan Industries, as assistant secretary to the Managing Director in 1955, becoming private secretary to Field Marshal Lord Alexander of Tunis in his role as Chairman of Northern Aluminium, 1957-1965. She then continued to work for Lord Alexander on a private basis until his death in 1969. She also helped to organise the Duke of Edinburgh’s first study conference on human and industrial relations in 1956.

In 1965 Seagrim was appointed as administrator of the newly formed Winston Churchill Memorial Trust, becoming Acting Director-General in 1983, before retiring in 1984. She died on 10 August 2011.