Culligan was born in Belledune, New Brunswick. In 1975 Culligan teamed up with Frank O'Dea to found the Second Cup chain of coffee shops. He eventually bought out O'Dea and then after building it to a 150-store chain, sold the business in 1988 to Michael Bregman, the founder of MMMarvelous Muffins.
He currently devotes himself full-time to painting and writing dividing his time between a cottage in the Muskoka Region of Ontario, his family's homestead built in 1824 on Chaleur Bay in northern New Brunswick, and a winter home in Florida.
- Geoff Matthews (October 16, 2002). "Bean There, Done That; Second Cup Coffee Baron Looks Back on His Beginnings". The Ottawa Sun. p. 41.
- Ron DeRuyter (October 29, 1997). "Reflections on success: Toronto businessman climbed off skid row to help launch major coffee shop chain". The Record – Kitchener, Ont.
- Culligan, Tom (2002), Teacups & sticky buns : mom's story, Culligan Pub, ISBN 978-0-9730250-0-2
- Elizabeth Cran (February 21, 2003). "Seeing a mother's life". The Guardian (Charlottetown, Prince Edward Island).