He had a passion for mental health, which he maintained throughout his medical career.

Dr Millar died unexpectedly on October 18, aged 60.

Born in Birchip, Dr Miller grew up at Rainbow, the second son of the district postmaster, Edward "Ted" Millar, and his wife Thelma.

He attended Ballarat Grammar School, where he achieved several honours which included dux, school captain and stroke with the school's first rowing crew in 1973.

After studying medicine at University of Melbourne, Dr Millar completed an internship at the Royal Women's Hospital and then at Ballarat Base Hospital in 1981, where he met his first wife, Janine Cosgriff, who was a nurse.

Dr Millar's time at Lakeside Mental Hospital inspired his interest in mental health.

He completed a diploma and ran a mental health practice in Webster Street. In 1996, he set up practice in Drummond Street with two colleagues before establishing his own practice Ballarat Mind-Body Medicine in Humffray Street North in 2005 with his second wife, Soni Stecker, as practice manager.

Dr Millar maintained his respect for traditional medicine but was always looking for ways to improve his knowledge by reading widely and researching innovative treatments.

Friends described Dr Millar as a country boy at heart with a truly noble spirit and idiosyncrasies admired by patients and friends.

Grampians Medicare Local chief executive officer Dr Andrew McPherson acknowledged Dr Millar's significant medical contribution to the Ballarat community for more than 30 years and said he would be deeply missed by the medical and wider community.

Dr Millar is survived by his wife Soni Stecker, who will continue his practice and legacy under the name Menssana, and his three sons, Jim, Huw and Lachlan, from his first marriage.

A public memorial service will be held on Friday at 1pm at the Ballarat Lodge, in Main Road.