Nicola Botterill has taken up the post of headmistress at Bruton School for Girls.
She succeeds John Burrough who retired at the end of last term, after 11 years at the school.
Mrs Botterill was deputy head of St Mary's Calne, a leading independent girls' boarding school in Wiltshire which she joined in 2007.
She has wide experience of working in girls' schools and having taught, and been taught, at both girls' and mixed schools is passionate about the benefits for girls of a single-sex education.
She said: "I feel enormous excitement about coming to Bruton School for Girls.
"Its happy atmosphere, dedication of the staff and welcoming sense of community immediately struck me.
"It is vital that every girl has excellent opportunities and that we support her to ensure she makes the most of them, so she leaves Bruton School for Girls as a happy, well-rounded individual, fully prepared for whatever she wants to do in life.
"And the school's ethos of 'it's not about who you are, it's about what you want to become' completely accords with my own beliefs."
Chairman of governors David Batten welcomed Mrs Botterill to her new position at the school.
He said: "The governing body and I were delighted to be able to make such a strong appointment.
"Nicola headed a large field of candidates and impressed us with her vision of the empowering nature of education, her determination to champion and lead a girls' school and her considerable personal qualities and experience."
Mrs Botterill, aged 44, and her husband, Edward, an officer in the Royal Regiment of Artillery, will live at the school.