He attended Sekolah Kebangsaan Hosba in Jitra and later Kolej Sultan Abdul Hamid, Alor Setar.
He was appointed to the Dewan Negara (the upper house) in August 1963, and completed two terms (of three years each) as a Senator.
He was actively involved in the formation of the Malaysia, serving as a diplomat to the United Nations and as the Malayan representative to the Cobbold Commission.
In October 2004, Mohamed Zahir died in office due to acute renal failure in Kuala Lumpur General Hospital.
[1] He was laid to rest beside the grave of his wife, Toh Puan Halimatun Saadiah Chik, at the Section 21 Muslim burial ground in Shah Alam, Selangor.