Sajid Javid has said he wants to SLOTXO see a return to normal "as quickly as possible" after replacing Matt Hancock as health secretary.
Speaking on Sunday, Mr Javid said he would do all he could to "deliver for the people of this great country".
His appointment comes after Mr Hancock stood down on Saturday for breaching Covid rules by kissing a colleague.
Mr Javid, who has had several key government roles, said his predecessor had worked "incredibly hard".
His return to the cabinet comes 16 months after his shock resignation as chancellor.
But Labour criticised the appointment, saying he had been an "architect of austerity" that weakened the NHS.
Mr Hancock announced his resignation after pressure had been building for him to quit following the publication by the Sun of pictures and a video of him and Gina Coladangelo, who are both married with three children, kissing.
The newspaper said the images had been taken inside the Department of Health and Social Care (DHSC) on 6 May.
Following the revelations, a number of Conservative MPs, as well as Labour and the Covid-19 Bereaved Families for Justice group, had called for Mr Hancock to go.
Ms Coladangelo is also leaving her role as a non-executive director at the DHSC.
Mr Hancock has ended his 15-year marriage to his wife, Martha, and the relationship with Ms Coladangelo is understood to be a serious one.