Roy was born at Kijabe and raised in the Narok and Loitokitok areas of Kenya. After attending Albany Medical College in the USA, Roy began his public health career in East Africa:

• District Medical Officer, Monduli, Tanzania. 1961-1963

• AMREF Flying Doctors. 1963-1965

• Private Medical Practice, Nairobi. 1965-1967

• Deputy County Health Commissioner, Albany, NY, USA. 1967-1974

• University of Nairobi Medical School faculty. 1974-1978

• AMREF, Founder of Community-Based Healthcare program. 1978-1986

• MAP (Medical Assistance Program), Nairobi, 1986–1991.

His first Retirement was in 1991-1998 before joining the KCMC (Kilimanjaro Christian Medical Center) faculty, Moshi, Tanzania, 1998-2000

His second retirement began in 2000. He currently resides in Arusha, Tanzania