Damian Hinds has replaced Justine Greening as education secretary.
His appointment comes after his predecessor spent two-and-a-half hours inside 10 Downing Street, after which she resigned.
Reportedly, Ms Greening refused to be moved to the Department for Work and Pensions.
As well as being a former member of the Commons Education Select Committee, Mr Hinds once chaired the All-Party Parliamentary Group on Social Mobility – a key issue for both the prime minister and Ms Greening.
In a tweet sent this evening, Mr Hinds said: "Delighted to be appointed Education Secretary – looking forward to working with the great teachers & lecturers in our schools, colleges & universities giving people the opportunities to make the most of their lives".
One union leader called for a period of stability for schools, telling the new secretary of state that “education does not need more upheaval”.
Paul Whiteman, secretary of the National Association of Headteachers, said: "For the past 18 months the DfE has been building a strong relationship with the profession. Free from needless 'big ticket' policy announcements significant progress has been made lately on areas like primary assessment. We have also seen fresh ambitions to improve careers advice and guidance, sex and relationships education and social mobility.
"Children need stability and their teachers can only provide that if the backdrop of education policy provides continuity for the profession.
"We look forward to developing the profession's relationship with Mr Hinds, building on the platform created by Justine Greening, working collaboratively with the profession and treating school staff with respect. New secretaries of state often feel that new announcements are obligatory. In 2018, where budgets are at breaking point and recruitment is still a massive challenge, education does not need more upheaval."
Meanwhile, Mary Bousted and Kevin Courtney, joint general secretaries of the National Education Union, called for Mr Hinds to engage with them and the teaching profession, and added: "Most crucially we hope he champions the need for extra funding for education and is able to get more money for education from the Treasury."
Geoff Barton, general secretary of the Association of School and College Leaders, said: "We welcome Damian Hinds to the post and look forward to working with him in a constructive manner.
"Our shared aim must be to ensure that school and college leaders are trusted to focus on what matters most – enabling teachers to help children and young people to achieve their best, irrespective of their background.”