Sajid Javid will replace Matt Hancock as Health Secretary, Downing Street has announced.
The Former Chancellor and Home Secretary resigned as finance minister last year after he refused to fire his political advisers as demanded by Boris Johnson.
A statement from 10 Downing Street said: " The Queen has been pleased to approve the appointment of the Rt Hon Sajid Javid MP as Secretary of State for Health and Social Care."
It comes after Hancock resigned as Health Secretary the day after video footage emerged of him kissing an aide in his ministerial office in a breach of coronavirus restrictions.
Images and video showed Hancock in an embrace with aide Gina Coladangelo last month, and the Health Secretary was facing increasing pressure to quit over the breaking of social-distancing rules.
Hancock wrote to Boris Johnson on Saturday and said: "The last thing I would want is for my private life to distract attention from the single-minded focus that is leading up out of this crisis."
He said: "We owe it to people who have sacrificed so much in this pandemic to be honest when we have let them down as I have done by breaching the guidance."
Johnson said he was "sorry" to receive Matt Hancock's resignation as Health Secretary.
He said Mr Hancock "should leave office very proud of what you have achieved - not just in tackling the pandemic, but even before Covid-19 struck us".
Johnson added: "I am grateful for your support and believe that your contribution to public service is far from over."
Johnson had previously refused to sack Mr Hancock, with his spokesman saying the PM considered the matter closed after receiving the West Suffolk MP's apology on Friday.
Reacting to the news, SNP Westminster leader Ian Blackford tweeted: "Massive failure of leadership by @BorisJohnson Hancock should have been sacked.
"A fish rots from its head. So does this UK Government.
"In Scotland of course we will face a choice on our future. We can say goodbye to the chaos and failure of UK leadership and take a step forward."
