Callaghan earned his BFA in painting at the Cleveland Institute of Art in 1999 and his MFA in 2005 at Kent State University. He teaches art to high school students at Lake Ridge Academy in North Ridgeville and makes a point to paint daily.

Strong studio habits are part of what Callaghan preaches in his 2013 book One Painting A Day (Quarry Books); his mother, he said, “instilled in me a work ethic that made this book possible.”

Over the years, Callaghan’s work has been shown in galleries in New York, Philadelphia, Washington D.C., Chicago and Cleveland. His paintings of the neighborhood around his home in Collinwood were exhibited in Timothy Callaghan: A Lovely Tremble, a Maria Neil pop-up show at the LaSalle Arts and Media Center.