Dame Helen Hyde, the former headteacher of Watford Grammar School for Girls, will play a leading role in Kavanah College, which is backed by the United Synagogue to open a new Jewish secondary free school in north-west London.
She will be joined as "educational lead" for the project by Marilyn Nathan, who has been an Ofsted inspector and a secondary school deputy head.
Maurice Ashkenazi-Bakes, Kavanah's project manager, said they would bring "an outstanding level of leadership experience as well as a diverse set of skills, which offer us the opportunity to develop the strongest possible programme for our future students."
The school - which is looking for a location accessible to families in north-west Barnet, South Hertfordshire and Harrow - plans to run an accelerated programme for gifted children.
Its social responsibility efforts would be helped by Dame Helen's charitable work with survivors of the Rwandan genocide and refugees here, Mr Ashkenazi-Bakes said.
The Department for Education is also considering a free school application from Barkai College.