Born in Accrington, Lancashire, Fish studied at Westminster City School before entering journalism.
There he quickly gained notice by providing the first reports of the murderer Dr Crippen's arrest in Canada.
In 1922, he fell out with the newspaper's owner, Lord Northcliffe, threatening to sue him for libel, but he was dissuaded and ultimately continued as editor until 1930.
He spent his retirement as a director of the Mail and during the Second World War advised the Ministry of Information and Press and Censorship Bureau.
These included the snowdrop, of which she built up a collection of species and varieties, making her a prominent galanthophile.