Cheng Man-sum will be Deputy Commandant of the Auxiliary Police Force from July 13.
The appointment fills the vacancy left by Yang Joe-tsi who became Commandant in April last year.
Mr Cheng, 55, is a partner of a local law firm.
He joined the Auxiliary Police Force as a constable in 1984 and was promoted to Superintendent (Auxiliary) in 2007 and to Senior Superintendent (Auxiliary) in 2011.
He became Chief Superintendent (Auxiliary) in 2015.
He has a wide range of operational and management experience, and was awarded the Long Service Medal for Auxiliary Police in 1999 and the First Clasp in 2009.
