Born in New Plymouth, Smither showed an early interest in art and in 1959 enrolled with the Elam School of Fine Arts Auckland where he was taught by A. Lois White, Robert Ellis and John Weeks.
His first group exhibition was in 1961 in New Plymouth although he spent this time residing in Auckland. In 1962 he spent most of the year in Patearoa, Central Otago, exhibiting paintings in Dunedin and returning late in the year to New Plymouth to commence his first rock drawings. His first rock pool paintings came in 1964, the same year his daughter Sarah was born.
Between 1964 and 1968 Smither worked on a number of commissons in the Taranaki area culminating in the Fourteen Stations of the Cross for St Joseph's Catholic Church. In 1970 Smither was represented in the New Zealand Pavilion at Expo in Osaka as well as being awarded the Frances Hodgkins Fellowship. Interested in marine biology and skindiving, Smither is intimately familiar with the Taranaki coastline and his rock forms, surging waves and the tranquility of still pools of water, are strong and consistent subjects throughout his career.
Michael Smither has been a regular exhibitor throughout New Zealand since 1961 and in 1969 he was included in an "Exhibition of New Zealand Modern Art" at the Smithsonian Institute, Washington. As well as the commissioned work in Taranaki Smither is represented in all public gallery collections throughout New Zealand. A major exhibition of his work toured he country in 1984.