John McLaughlin, the longtime host of the pioneering political roundtable show “The McLaughlin Group” has died at age 89.

The show’s official Facebook page announced the death Tuesday afternoon, saying it had happened earlier in the morning. No cause of death was immediately released and memorial services were still pending.

“As a former Jesuit priest, teacher, pundit and news host, John touched many lives. For 34 years, ‘The McLaughlin Group‘ informed millions of Americans. Now he has said bye bye for the last time, to rejoin his beloved dog, Oliver, in heaven. He will always be remembered,” the page said.

Through those decades on PBS, he developed signature lines such as the closing “bye bye” and the bellowing “Issue One…,” such intellectual tics as his obsession with the effects of “Euro 92,” and such nicknames for panelists as “Freddie ‘the Beetle’ Barnes.”

They all made Mr. McLaughlin a larger-than-life figure, and one often-parodied by comedians such as Dana Carvey, and appearing as himself on the show in movies such as “Dave” and “Watchmen” and TV shows like “Cheers.”

Longtime panelists also included Morton Kondracke, Eleanor Clift, Robert Novak, Pat Buchanan and Jack Germond. Frequent panelists from The Washington Times included former editorial page editors Tony Blankley and Tony Snow, current online opinion editor Monica Crowley and current national-security team-leader Guy Taylor.

“When I was growing up, my family had a regular Sunday morning ritual: church, pancakes, and ‘The McLaughlin Group.’ Years later, I was deeply honored when he invited me to join the show as a regular panelist, a position I enjoyed for about four years,” Ms. Crowley said.

“John McLaughlin invented the modern panel-based public affairs show, imbuing it with smarts, humor and his indomitable spirit. He was a towering personality who changed the way we think about — and talk about — national and world events. It was a privilege to have been part of an American institution. Godspeed, Dr. McLaughlin,” she concluded.

Mr. Taylor, who became an occasional guest on the show in recent years, offered condolences to all who loved him and similarly recalled being flattered by being invited to be on the must-watch political show.

“The first time John called me on the telephone a few years back, it was like a dream. There he was, just suddenly grilling me with a hundred questions to see if I could make it as one of his guests. I was so flattered. But I had to keep up. I didn’t realize until after the call that I’d just been ranting away about 100 things in the news with one of my idols,” Mr. Taylor said.

“He just knew everything and everyone there ever was to know in Washington for about the past 60 years. And he was so generous with it, he’d just so easily pull younger journalists less than half his age right into his fold. And once you were in there, you felt like you were dancing through the ‘Powers that Be,’” he concluded.

Mr. McLaughlin was ordained a priest with the Society of Jesus and took one of his first media jobs as a writer and later assistant editor with the order’s current-affairs magazine America. He left the Jesuits in the mid-1970s to enter politics, after having already defied the order by running for Congress and working as a speechwriter for President Richard Nixon.

“The McLaughlin Group” began in 1982 on PBS and has been a weekly staple of its lineup ever since. He also had an one-hour interview series on PBS for much of the period — “John McLaughlin’s One on One” ran from 1984 to 2013 — and it showed him in a less-contentious format.

Mr. McLaughlin missed the first episode of “The McLaughlin Group” in its entire run just last weekend, starting the show with a written introduction and apologizing for his illness.

“As the panel’s recent absences attest, I am under the weather,” the message read. “The final issue of this episode has my voice, but please forgive me for its weaker than usual quality. Yet my spirit is strong and my dedication to this show remains absolute!”

The host job was left in the hands of Tom Rogan for that show. There was no immediate word Tuesday on whether that arrangement would continue.

At his personal site Tuesday, Mr. Rogan shared clips of a number of his favorite moments, including one moment in which Mr. McLaughlin ended the show with “Rogan is right; bye, bye.”

“A simple sentence, but it meant a lot to me,” Mr. Rogan wrote Tuesday.