Russell Johnson, lower right, is shown with other “Gilligan’s Island” cast members in 1978. The show, which aired on CBS from 1964 to 1967, ran for decades in syndication and spawned several movies. (ASSOCIATED PRESS)

Russell Johnson, a ruggedly handsome character actor best remembered as the Professor on the sitcom “Gilligan’s Island” and was its last surviving male cast member, died Jan. 16 at his home in Bainbridge Island, Wash. He was 89.

His agent, Mike Eisenstadt, confirmed the death but did not disclose the cause.

“Gilligan’s Island,” which shipwrecked a cross section of society on an uncharted South Pacific isle, will never be mistaken for sophisticated comedy or sophisticated farce. Even the late Bob Denver, who had the title role of the inept first mate, called the show “silly and inane.” And Mr. Johnson once said that after reading the first script, “I had no faith in it whatsoever.”

Nevertheless, “Gilligan’s Island” proved irresistible to many viewers. It aired on CBS from 1964 to 1967 and has been in syndication ever since. The sitcom also spurred occasional TV movies that reunited most of the original cast and bore such accurate if unlikely titles as “The Harlem Globetrotters on Gilligan’s Island” (1981).

For better or worse, “Gilligan’s Island” was one of the most enduring sitcoms in TV history. The show’s appeal, Mr. Johnson later told CNN, “may have to do with satisfying people’s fantasies. They can join us on an island and enjoy the adventures and still feel safe.”

Russell Johnson, who portrayed the Professor in “Gilligan's Island,” appears at a launch party for “Gilligan's Island: The Complete First Season,” in Marina Del Rey, Calif., on Feb. 3, 2004. (JIM RUYMEN/REUTERS)

Mr. Johnson had a key supporting role as a high-school science teacher (real name Roy Hinkley) who during the run of the series fashions a radio from a coconut and a Geiger counter from bamboo. Yet for all his MacGyver-like prowess, he can’t seem to patch a hole in the boat that marooned them.

As he jested with a reporter years later: “I just say, ‘Fix the boat? Wow! That never occurred to me!’ ”

In addition to Denver, the other cast members included Alan Hale Jr. as the misfit skipper Jonas Grumby; Jim Backus and Natalie Schafer as the millionaires Thurston Howell III and Lovey Howell; Tina Louise as the buxom starlet Ginger Grant; and Dawn Wells as the alluring country girl Mary Ann Summers.

The humor was unremittingly low-brow and slapstick. To rub in the point, series writer and producer Sherwood Schwartz apparently named the stranded boat the S.S. Minnow after Newton Minow, the chairman of the Federal Communications Commission who famously called the prime-time TV schedule “a vast wasteland.”

Although “Gilligan’s Island” won high ratings, it was canceled because of scheduling conflicts with the western “Gunsmoke” — a favorite of CBS chief executive William S. Paley.

“Gilligan’s Island” overshadowed Mr. Johnson’s long career. For years, he said he resented not only the way it seemed to limit his more-serious acting aspirations, but also that he and other cast member were left out of the bulk of the syndication profits. He cooled off in time.

“It helps that I had 15 years in the business before ‘Gilligan’s Island’ to get some of that out of my system,” he said.

Russell David Johnson was born Nov. 10, 1924, in Ashley, Pa., where he was the oldest of seven siblings. He was 8 when his father died, and was sent to a boarding school for “poor, white male orphans.”

After graduation, he served in the Army Air Forces as a bombardier in the Pacific during World War II. He made dozens of bombing runs, he told interviewers, before his plane was shot down in the Philippines during a mission over Japanese-held territory. He said he received the Purple Heart for injuries that included two broken ankles.

On the GI Bill, he studied drama in Los Angeles and made his film debut in “For Men Only,” a 1952 drama about fraternity hazing. That same year, he played a heavy in “Loan Shark,” starring George Raft.

Mr. Johnson began a journeyman career in Audie Murphy westerns (“Tumbleweed,” “Ride Clear of Diablo”) and science-fiction fare, such as “This Island Earth” (1955) and the uproariously low-tech “Attack of the Crab Monsters” (1957), directed by Roger Corman.

In addition to feature films, Mr. Johnson was a prolific TV actor in series such as “Alfred Hitchcock Presents,” “The Twilight Zone,” “Lux Video Theatre,” “Black Saddle,” “The Outer Limits” and “77 Sunset Strip.”

His first marriage to Edith Cahoon, ended in divorce. His second wife, actress Kay Cousins, died in 1980. Two years later, he married Constance Dane. Besides his wife, survivors include a daughter from his second marriage; a stepson; and a grandson.

A son, David, died of AIDS in 1994. Mr. Johnson became involved in fundraising work for AIDS research.

After his run in “Gilligan’s Island,” Mr. Johnson appeared on television series including “The Jeffersons,” “Dynasty” and “Roseanne,” and was a busy actor in voice-overs for commercials and corporate films. He also played Adm. Ernest J. King in the World War II movie drama “MacArthur” (1977), starring Gregory Peck.

In 1993, he collaborated with writer Steve Cox on the memoir “Here on Gilligan’s Isle.” Mr. Johnson was droll about the writing process.

“Leo Tolstoy has nothing to worry about,” he quipped.