Preston will join as executive editor later this year, while Bob Tyrer will remain in the same role alongside Preston.
The Sunday Times is preparing a refresh of its design and navigation later this month and this follows last November’s hire of Lorraine Candy, the editor of Elle, as luxury content editor and editor-in-chief of Style magazine.
Preston has been editor of Radio Times since 2009, joining two years before the BBC sold the title to private equity company Exponent. That deal saw the creation of Immediate Media, the current publisher of Radio Times.
Before the Radio Times, Preston worked for over 20 years in newspapers, 12 of which were at The Times, The Sunday Times' sister newspaper, including eight years as deputy editor. Last year he was awarded the editors’ editor by the British Society of Magazine Editors.
Martin Ivens, editor of The Sunday Times, said: "Ben is a hugely respected and versatile editor, able to combine incisive news judgment with a flair for engaging features, investigations and campaigns.
"His breadth of experience, across both newspapers and magazines, is a perfect match for The Sunday Times and I am delighted that he will be bringing his many talents to the paper."