Mrs Davidson's retirement will coincide with the amalgamation of Brighton School and Ocean View School in term 3.
Since starting at the school in 1988, she has seen "huge changes in education", and referred to the implementation of Tomorrow's Schools policy and the increased access to information technology resources, as two of the most significant changes school leaders faced in the past two decades.
The school community's demographic had also changed during her tenure, and parents now drew on a wide range of employment experiences when serving on the school's board of trustees.
Mrs Davidson said she had been well-supported by the board of trustees.
Mrs Davidson was formerly a teacher and principal at Berwick and Henley Schools, and trained at the Dunedin College of Education (now the University of Otago College of Education) in the 1960s.
She may have involvement with teaching in future, and is looking forward to spending more time "biking around Central [Otago]".
After the merger, the yet-to-be-named school - an application for the new name was lodged with the Ministry of Education last Monday - will have about 75 pupils. Brighton School has 56 pupils.
Waitati School principal David Grant will begin duties as principal at the new school in late July.
"It is a dream job and a real honour to be chosen as a school's founding principal. You could say it's a community-driven community, and I look forward to working in partnership with staff, the board and community."
He said it was "too early" to comment on staff retention after the merger, or future education programmes at the new school.
Mr Grant has been principal at Waitati School for three years. He was raised in Dunedin and gained teaching qualifications from the College of Education.
