He first found work as a mailman.

He would later coach physical education and teach math at Corpus Christi School, a Catholic elementary school in Pacific Palisades, California. He costarred with Dwayne Hickman on The Many Loves of Dobie Gillis in 1959.

Denver played the role of Maynard G.

Krebs, while Hickman played Dobie Gills.

Hickman was also a Loyola graduate.

Credited as "Robert Denver," he landed a small role in the 1963 Jimmy Stewart film, Take Her, She`s Mine, playing a beatnik poet working at a coffee shop named "The Sleeping Pill." Denver appeared in the 1964 beach movie For Those Who Think Young with Tina Louise prior to the development of Gilligan`s Island. When Dobie Gillis ended in 1963, Denver landed the role of Gilligan on Gilligan`s Island. After the conclusion of Gilligan`s Island, he performed in other shows such as The Good Guys (1968–1970) and Dusty`s Trail (1973) (a facsimile of Gilligan`s Island, with the basis of a lost wagon train).

He also starred in a children`s program, Far Out Space Nuts (1975), which was essentially Gilligan in space.

Although appreciated by Bob Denver fans, none of these shows matched the wider audience success of his earlier roles. Since Gilligan`s Island, Denver has played the lead in Woody Allen`s Play It Again Sam on Broadway, done years of touring theater and dinner theater, occasional Gilligan and Dobie reunion shows, reprised Gilligan on an episode of Baywatch and the feature-film parody Miss Cast Away (2004). In 1998, Denver was arrested for having a parcel of marijuana delivered to his home.

He originally said that the parcel had come from Dawn Wells (who had played "Mary Ann" on Gilligan`s Island) but later refused to name her in court, and testified that "some crazy fan must have sent it".

The police reportedly found more of the drug and related paraphernalia in Denver`s home.

He pleaded no contest and received six months probation. Later on in his life, Denver returned to his adopted home of Princeton, West Virginia.

He became a FM radio personality.

Along with his wife Dreama, they ran a small "oldies format" station, WGAG-LP.

He also earned a small income making public appearances, often costumed as Gilligan. In May 2005, Denver underwent quadruple heart bypass surgery, and was consequently diagnosed with throat cancer.

He died September 2, from pneumonia and squamous cell carcinoma of the larynx[3] at Wake Forest University Baptist Hospital in Winston-Salem, North Carolina at the age of 70, surrounded by his family — his last wife (of 28 years), the former Dreama Peery; and his children of 4 different marriages; Patrick, Megan, Emily, and Colin.