Dr. Benton C. Quest is Jonny's father and a scientific genius who works for the U.S. Government. He is considered "one of the three top scientists in the world", with interests and technical know-how spanning many fields. Raising Jonny and Hadji as a widowed father, he is benevolent, conscientious and decent, even though he is ready, willing and able to take decisive action when necessary for survival or defense. Dr. Quest was voiced by John Stephenson for five episodes, and by Don Messick for the remainder of the series.