The well-respected and long-serving headmaster retired from the Wellington boys' school last year after 23 years at the helm.
Mr Moses was awarded a New Zealand Order of Merit in 2009 for services to education, and in 2015 he won the education section of the Wellingtonian of the Year awards.
He has taught at a wide variety of schools, including Auckland Grammar School, MacLean's College, Mahurangi College and Waihi College.
He is chairman of the Professional Advisory Group looking at the NCEA Review, he has served on the New Zealand Qualifications Authority Working Party, the Secondary Principals' Association of New Zealand executive, the Association of Boys' Schools national chairman, the International Boys' Schools Coalition executive, and is a member of the board of the Bible Society.
Board of trustees chairman Richard Wingham was delighted to have Mr Moses accept the role.
"Roger's outstanding track record in boys' education is a reflection of his skill and dedication to the job.
"He represents a fantastic option to provide continuity of leadership at King's between Dan Reddiex leaving at the end of term 1 and a new rector starting in term 3.
Mr Reddiex will leave on April 12 to take up the principalship of Dilworth School, a private Anglican boys' boarding school in Auckland.
Mr Wingham said the board now had a shortlist of "strong" applicants for the permanent replacement of the rector in term 3.
It was hoped an announcement would be made next month, he said.
