The headteacher of Trinity School will also lead St Martin's Primary from January 2022 until the school appoints a replacement for Jenny Posner.
Mrs. Posner is leaving St Martin's to replace the retiring Mike McDermott as headteacher of Samares.
Katy McMahon, who has led Trinity School since January 2016, will have the role of 'leading headteacher' for Trinity and St Martin.
St Martin's Deputy head Karen Cooper and Trinity Deputy head Chris Godden will take on a 'Head of School' position at their respective schools.
"The two schools, St Martin’s and Trinity, already share a curriculum model, frequently have shared training and have mentoring experience across the two schools.
"These arrangements build on a well-established partnership and will provide the best possible support to the children of both St Martin and Trinity Schools." - Seán O'Regan, Group Director of Education.
John Baudains and Vicki Charlesworth were also appointed as Leading Headteachers last year.
Mr. Baudains is in charge of La Moye and Bel Royal, with Mrs. Charlesworth leading Les Landes and St Peter.