Dennis was born in Toronto, Canada and came to the US in 1960. He attended the University of Michigan where he received his Architectural degree and then the University of Pennsylvania for Master degrees in Architecture and City Planning. After a career in Architecture it wasn't until his early sixties that Dennis began to pursue his lifelong dream to paint. With the encouragement of his wife Linda, he enrolled in Studio Incamminati in Philadelphia in 2004 where he studied under world renowed portrait artist Nelson Shanks for four years.
Dennis spends winters painting in Florida, and summers in Nantucket. His landscapes are painted en plein air and often completed in his studio. He paints both finished and sketch portraits, and although he prefers to paint his portraits from life, he also does them from photographs.
Dennis continues to learn from artists he admires and has taken workshops from John Osborne, Anne Blair Brown, Colin Page, Frank Gardner, Thomas Jefferson Kitts, Jeffrey Watts, Scott Christensen, Carolyn Anderson and Daniel Greene. He finds great inspiration in the works of Joaquin Sorolla and Nicolai Fechin. He is a member of the Arists Association of Nantucket where he received the 2011 Robert C. McDougall award for most promising new artist and then the 2015 Pat Gardner "En Plein Air" Award.