Murray Gainer was born in Edmonton, Alberta, and grew up on the prairies. He initially received formal training in the visual arts through classes sponsored at the local art gallery. Gainer later graduated with distinction in the Bachelor of Fine Arts (BFA) program at the University of Alberta. Gainer attended two consecutive summer programs at the Emma Lake campus of the University of Saskatchewan.

Gainer subsequently moved to Toronto and worked as a sculpture assistant while pursuing his own work at the same time. He has been represented in shows at the London Regional Art Gallery and several shows sponsored by Gallery Quan in Toronto.

Over the years, Gainer has experimented with sculpture, collage, and highly abstract two-dimensional imagery, and often employs themes suggesting aspects of landscape. 

Recent paintings tend to be increasingly representative. Gainer uses pictures, photographs, sketches, as well as memory and imagination to create images which ultimately are largely imagination-based. Gainer has traveled extensively in the last several years, and in addition to the impressions and memories created, photographs and sketches from these travels tend to be incorporated in current work.