Nabors, 82, and Cadwallader, 64, tied the knot earlier this month, according to an interview the former television star did with Hawaii News Now.
The couple, who live in Honolulu, have been together for more than three decades and reportedly traveled to the state of Washington -- where gay marriage became legal in December – to exchange vows at the Fairmont Olympic Hotel in Seattle.
"We've been together for 38 years, and I'm not ashamed of people knowing, it's just that it was such a personal thing, I didn't tell anybody," Nabors told the newspaper. "I'm very happy that I've had a partner of 38 years, and I feel very blessed. And, what can I tell you, I'm just very happy."
Nabors has never publicly acknowledged his homosexuality in the media, but said he never really tried to keep it secret.
"I haven't ever made a public spectacle of it," he said. "Well, I've known since I was a child, so, come on. It's not that kind of a thing. I've never made a huge secret of it at all."
According to the interview, Nabers and Cadwallader met in 1975 when Cadwallader was a firefighter; he later worked for Nabors, and then they started dating.
While best known for his portrayal of Gomer Pyle, Nabors also starred in his own spin-off show, “Gomer Pyle, U.S.M.C.” The show aired from 1964 to 1969 and ran for a total five seasons (150 episodes).
Nabors also made frequent appearances on such shows as "The Carol Burnett Show," "The Sonny and Cher Show" and "The Love Boat" and hosted his own series, "The Jim Nabors Hour," from 1969-71.
He is also known for his baritone voice and has recorded more than 25 albums as well as performed in numerous musical theater productions.