Grignon was born in Toronto, May 5, 1948. He began painting in oils at thirteen and built several "Old West" model railroads as a teenager. Self-taught in technical skills, his "inner artist" was awakened during a year at Toronto's New School of Art, immersed in figure drawing and abstract expressionist painting, and another year in theatre production.

In 1973, Paul ventured west to British Columbia, and soon began building a home on Gabriola Island. He worked at tree planting and construction for several years to support his wife and four children, until physical injury forced him to try to make a living from his art.

He began in 1982, with a year spent building a diorama of native life in the Nanaimo Museum and has been busy since. Although his versatility leads him to take on a wide variety of artistic projects, often in aid of environmental causes, his core work is to explore and interpret in paint, the powerful landscape in which he lives. Over the years, recogniton of Paul's work has grown steadily, as more and more people are drawn into the distinctive light, mystical intensity, and passion of his painting.