Jim Toomey was born and raised in Alexandria, Virginia. He launched Sherman's Lagoon in 1991 and was picked up by Creators Syndicate later that year. An engineer, a philosopher, a surfer, a scuba diver, and a sailor, Toomey lives in Annapolis, Maryland, with his wife and daughter.

He has been twice awarded the Environmental Hero Award, given by the National Oceanic and Atmospheric Administration, "for using art and humor to conserve and protect our marine heritage."