Susan Acland-Hood, who has been interim permanent secretary at the Department for Education since September, has been appointed to stay in the top role.
Acland-Hood was brought into the department in August as second perm sec to help deal with the aftermath of a row over A-Level grades, and children's return to schools in September.
She was previously head of HM Courts and Tribunals Service, having previously spent time as a DfE director and senior adviser on education policy at No.10.
She became interim perm sec in early September, after Jonathan Slater was asked to step aside as DfE's top civil servant because of the grades row.
A DfE spokesperson said at the time that the prime minister had decided he wanted "fresh official leadership" for the department.
Cabinet secretary Simon Case said Acland-Hood would bring "a wealth of relevant experience to the role and a genuine enthusiasm for the agenda having served in the department previously".
"Under her leadership, I am confident that the department will deliver high-quality education and children’s services for everyone.”
Education secretary Gavin Williamson said Acland-Hood was an "outstanding civil servant with extensive experience across government and education policy".
“Having worked closely with Susan over the last few months, I know she is a great leader and has the skills and experience to really deliver the government’s ambitious agenda to level up education across the country, giving every child an equal opportunity to succeed," he said.
Acland-Hood said she was "honoured and delighted" at the appointment.
“Shaping the department and supporting its committed, brilliant staff to do the best possible job for children, and for students and learners of all ages, has never mattered more, and I take up the challenge with passion and determination," she said.