Gregory J. Hobbs Jr. (December 15, 1944 – November 30, 2021) was an American lawyer and judge who served as an associate justice of the Colorado Supreme Court from 1996 to 2015. A leading expert on Colorado water law, Hobbs practiced environmental, land use, transportation, and water law for more than two decades before his appointment to the bench. He conveyed his expertise not only on the state's highest court, but also through his extensive publications, presentations, and professional and community service.