The former Sun on Sunday editor moves into the position to replace Tony Gallagher, who has been named as the new deputy editor of The Times.
She becomes the paper’s second female editor after Rebekah Brooks, who led the publication from 2003 to 2009. In 2003 Ms Brooks was cleared of all charges after being implicated in the phone hacking scandal at The News of the World, and now serves as parent company News UK’s CEO.
Her appointment also means five of the UK’s leading publications have female editors – a list which includes The Mirror, The Guardian, The Sunday Times and the Financial Times
Ms Newton, who has worked at The Sun for more than 20 years and has been editor of The Sun on Sunday since 2015, said the paper "has been such a huge part of my life".
She added: "I feel humbled at the thought of helping build the newsroom of the future, to serve our readers across the globe. I can't wait to get started."
Meanwhile Tony Gallagher said he was “delighted” to have been appointed to his new position, which was left vacant after predecessor Emma Tucker was named the new editor of the Sunday Times.
Mr Gallagher, who previously served in senior roles at The Daily Mail and The Daily Telegraph before undertaking a brief stint working in the kitchens of tapas restaurant Moro in north London and then moving on to edit The Sun, added The Times was “the first paper I subscribed to as a child”.
Rupert Murdoch said: "As editor of The Sun, Tony Gallagher has expertly steered the paper through two elections and the many dimensions of Brexit, ensuring that the news is always engaging and relevant for our readers.
"He is a newsman to his core and has edited with conviction, skill and energy.
"His experience across Fleet Street titles will be an asset to The Times."
Ms Brooks added: "I would like to thank Tony for his time as editor-in-chief of The Sun.
"Over the last four years, Tony has shown commitment and passion, editing through an exceptional news agenda and the paper's 50th anniversary.
"He joins John Witherow on The Times, where they will make a formidable team."
The reshuffle comes after Martin Ivens, editor at The Sunday Times for seven years, stepped down from the role to join the newspaper’s board as a director.