"Professor" Roy Hinkley Jr., M.A. B.S. Ph.D. is one of the main characters on the show. He is a science teacher at a high school, and because of his academic experience he is almost solely referred to as "The Professor" by the Castaways instead of his real name.
The Professor was a high school science teacher who originally booked his tour on the Minnow to help with his research on his book "Fun With Ferns." The Professor is very smart, kind, sensible, and rarely gets frightened. The Professor is very grounded in reality, and doesn't believe in superstitious things like voodoo or ghosts. He always strains to find a sensible, logical explanation for almost any situation.
Although very analytical and logical, the Professor is not completely stoic or humorless. He does have his moments where he becomes the "straight man" in the "Laurel and Hardy" antics of Gilligan and the Skipper. He gets his moments to break away from being serious, like scaring Gilligan with a giant hypodermic, but other times, removing Gilligan's hat so the Skipper can swat him or sighing as their conversations drift way off subject.
Dr. Roy Hinkley, a 45-year-old high school teacher, holds six degrees in the fields of chemistry, botany, biology, psychology and geography. He was a genius from a very early age: He has a B.A. from USC, a B.S. from UCLA, an M.A. from SMU, and received his Ph.D from TCU at the age of 15. He has also spent two years on an Egyptian expedition. He also holds a master's degree in psychology and can speak fluent Marubi, Papuan, and Katubi, to name a few. Back home, he is the number one man on his chess team, and he was the youngest Eagle Scout in the entire city. At the time of the shipwreck, he was considered a Scoutmaster. He has never been married nor does he seem to be in a relationship by the time he arrived in Hawaii. He wrote a book called, "Rust, the Real Red Menace," and was writing another book "Fun with Ferns," which was the reason for taking the 3-hour tour. During his first week on the island, he discovered five different mutations of ragweed. The Professor shows very little knowledge of sex, sea navigation and finance; he is oblivious to the constant pursuit by Ginger. Still, the Professor is the only rational person on the island, and without his scientific skills and leadership ability, it is unlikely that the castaways would ever stand a chance of survival, let alone a rescue. On the island, he has acted as a judge, doctor, dentist and psychiatrist.
With the exception of dream sequences, the Professor wears a white, long sleeved, dress-like shirt, khakis, and blue boat shoes throughout the entire show. During cool nights on the island, he wears a brown tweed sports coat. He also has a set of white pajamas with rosette decorations.
The Professor doesn't seem to bring a lot of stuff with him besides a few books (although a few were probably already on the Minnow), rubber gloves, a magnifying glass and a slide rule. He also wears a calendar watch.
- In the unaired pilot, he was played by John Gabriel and was a high school teacher called "the Professor."
- In high school, he was on the chess team. Despite being an intellectual, he is also more physical fit than any of the male Castaways.
- When asked how long he could kiss Ginger Grant in Castaways Pictures Presents, he mentions having been a scuba diver.
- He also owns a calendar watch and a pocket knife and a diary
- In common with the Skipper, he enjoys eating coconut-pineapple pie. In Voodoo, Gilligan says his favorite dish is halibut in kumquat sauce.
- The Professor is left-handed.
- Among his inventions are a bamboo Geiger counter, a bamboo hypodermic syringe, clamshell prongs, a record player made from the Minnow's steering wheel and bamboo test tubes among other objects.
- In the Lord Beasley episode, the Professor passes out from drinking too much fermented berry tea. In the Nyet, Nyet, Not Yet episode, he confesses he is allergic to alcohol.
- In Two on a Raft, it is mentioned on the radio that he is a research scientist of no particular field and a Scoutmaster.
- It is a common joke on the show that the Professor can make anything from coconuts and bamboo, as well as use his advanced scientific knowledge and prowess to explain logic, but he couldn't fix a 2-foot hole on a boat. (Actor Russell Johnson later joked that if he was stuck on an island with Dawn Wells and Tina Louise, he would be in no hurry to fix the boat.) Even then, some of his logic has come to question in certain episodes.
- The Professor has a habit of dismantling and studying everything that comes across the island including the NASA Space Probe, the robot and the XJP Jet Pack.
- In The Invasion, the Professor has some pet canaries.
- In Rescue from Gilligan's Island, when the Skipper and Gilligan visit the Professor in a college laboratory, Gilligan knocks over a pile of test tubes- this was a dummy set by the Professor just set up for Gilligan!
- Ironically, in real life, Russell Johnson was a USAF crewman on a bomber that crash landed in the Phillippines during World War II.