Betty Marsden was well-known for comedy roles on stage and radio
Miss Marsden had been suffering from heart problems and pneumonia but was thought to have been recovering well.
She died suddenly in the bar of the Actor's Charitable Trust Home in Northwood, north-west London, while having a drink with some friends.
She was still working as a actress, recording her role as a "hag" just ten days ago for a radio adaptation of the Narnia Chronicles.
But she will always be remembered for the string of comic voices she put on for the 1960s BBC radio series, Round the Horne.
One of her most famous roles in the series was that of "Fanny Haddock", a spoof of the celebrity chef of the time, Fanny Craddock.
Active career
Miss Marsden was born in Liverpool and came to comedy after years as a stage actress. Her big break came in 1938, when she was an understudy in a West End play, and was called up to replace the leading actress who had fallen ill.
During the Second World War, she regularly entertained the troops, and it was at this time that she met her husband, an army doctor from Edinburgh, Dr Jimmy Wilson Muggoch.
They had two children and were married for three decades.
Miss Marsden also starred in several television and stage roles, including the Joe Orton farce, What The Butler Saw, at the Royal Court Theatre.