Gabriel Leon "Gabbie" Plaa (May 15, 1930 – November 11, 2009) was an American-Canadian toxicologist. A specialist of hepatotoxicity, he held various administrative position at Université de Montréal from 1968 to 1989, receiving the grade of professor emeritus upon his retirement in 1996. Over the course of his career he was president of several scientific society and served in editorial capacity for numerous scientific journals. Amongst many awards, he was the first recipient of the Society of Toxicology's (SOT) Achievement Award, an award granted to a "promising young scientist".