Doherty Engineering Inc. (DEI) is a Canadian engineering consulting firm based in Mississauga, Ontario. Founded in 2007 by Paul Doherty, the company leverages over 20 years of experience to provide a variety of engineering services across industrial, institutional, and commercial sectors.

DEI specializes in mechanical and electrical engineering, focusing on HVAC systems, electrical distribution, and renewable energy solutions. They incorporate eco-friendly practices into their projects, offering options like solar thermal collectors and geothermal systems. The firm also has expertise in LEED-certified projects and provides solutions for decarbonization and energy efficiency.

In addition to their engineering services, DEI is dedicated to community involvement, supporting charitable causes and educational initiatives. Paul Doherty actively participates in mentoring programs for youth, promoting teamwork and strategy development through ice hockey.