The Professor is a high school teacher, 35 years old, from Cleveland, Ohio. His name is Roy Hinkley, but it is a name he seldom hears because the rest of the group has nicknamed him "The Professor" and that's the only name they use.

While growing up, the Professor was the youngest Eagle Scout in the entire city, and there is still a great deal of Jack Armstrong, the All-American Boy, in him. He has a strictly scientific and logical approach to life. To a great extent, this explains why he has never married. On several occasions he became interested in several girls, but when he began to think of a teacher's salary and the problems this would cause in marriage, that always prevented the wedding bells. This true-blue-harry attitude about girls and other issues of moral principle give the Professor a righteous and somewhat "square" attitude. Mary Ann treats the Professor like an older, smarter brother; and although Ginger might have a more amorous attraction to him, he seems almost oblivious to her advances.

The Professor is well versed in all the sciences: chemistry, botany, biology and geography. Unfortunately he is not well versed in the science of sea navigation - this is the Skipper's expertise! He also attended several colleges and universities for quite a few years and earned the following degrees: he has a B.A. from the University of Southern California, a B.S. from the University of California at Los Angeles, an M.A. from Southern Methodist University, and a PhD from Texas Christian University. His specialty is dull metals and he was at work on two books. The first book was entitled: "Rust: The Real Red Menace, " and his second book (the reason he took the "three-hour island tour") is entitled: "Fun With Ferns" (He is also particularly interested in island areas: the sand and soil, the vegetation, local natives and their customs, etc. That is the reason for his trip to that locality, and the real reason he happened to be aboard the S.S. Minnow.

In the group of castaways, the Professor is the voice of reason. Very often he is the one who prevents the rest of the group from taking rash actions. The others look to him and his great store of scientific knowledge, especially as it might affect the possibility of rescue. And it is to this end that the Professor dedicates himself. He also has an aptitude of gadgetry (see below) which is an obvious asset to the castaways.

He spends much of his time working with minerals and other raw materials on the island, in hopes of inventing flares, dye marker, signals, etc. This dedicate and sincerity in these scientific experiments often gives him an air of preoccupation.