On Jan. 19, the night before he is sworn in as president, Ronald Reagan will be honored at a fancy bash. Everyone who is anyone -- movie stars, opera singers, tycoons and politicos -- will be there in top hats, tails, tiaras and sequined gowns.

No, not at New York's Plaza Hotel, nor the Hilton in Beverly Hills, nor even the Kennedy Center in downtown Washington. The site of this gala will be the Capital Centre in Landover, that proud home of Bullets, Capitals, ice shows and rodeos, in the heart of Prince George's County.

Prince George's County?

"Well, what's wrong with that?" demands County Executive Lawrence J. Hogan. "We aren't exactly unrefined in these parts, you know."

"Hey," adds Capital Centre president Abe Pollin, "We've had tuxedos here before."

"Say what?" asks Harriet Jackson, manager of a dilapidated low-income housing project down the road from Pollin's place. "Sinatra and Johnny Carson are coming where?"

Officially billed the presidential inaugural gala, this unlikely Republican celebration in Landover will be attended by the president-elect and Mrs. Reagan, the vice president-elect and Mrs. Bush, and more than 18,000 very elite, chic and powerful guests who, by strict invitation only, have put up $100 a head just to be there.

In one sense, it seems appropriate that this, the largest of the inaugural events, is held in the suburbs of Washington. Much of Reagan's support in the November election, after all, came from the suburbs.

But as a place to celebrate Republican rebirth, these particular suburbs are a somewhat ironic choice. Prince George's has a higher percentage of blacks and blue-collar workers than any other suburb in the metropolitan area, and in many places has more in common with inner city Washington, with its low-income housing and crime, than the wide open spaces, rambling homes and lush parklands of Montgomery and Fairfax counties.

Although more people live in Prince George's County than any other Washington suburb, the jurisdiction has long suffered a reputation as the ugly sister of national capital residences. It's simply the kind of place where most people prefer beer to champagne.

Of course, organizers of the gala had no choice. The only arena in the Washington area large enough to hold so many guests is the Landover facility, which was built eight years ago and targeted specifically for the suburbs so that concertgoers and sports enthusiasts could avoid journeying to the inner city.

But even for the Capital Centre an inaugural party is something out of the ordinary. The last time anything occurred in Landover that remotely resembled a conservative vision of refinement was when the mythical fat lady sang so joyously during the Washington Bullets' championship basketball season nearly three years ago.

"The party may as well be held on Satellite 3, as far as the rest of the county is concened," says Dale Wright, an officer of the Landover Mall Merchants Association, located a few blocks away from the Centre.

"I mean, Prince George's is more of a rural, blue-collar, common-man kind of place. It's not a major stop on the jet setters' tour."

Neither is it a hotbed of Republican Party activism. Traditionally a Democratic party stronghold, Prince George's County residents voted heavily for Jimmy Carter in the November election, which was a prime reason Carter was able to carry Maryland, one of five states in which he proved more popular than Reagan.

The Jan. 19 gala will be produced and directed by Frank Sinatra, who reportedly favored the Capital Centre over the Kennedy Center for the celebration because of the larger seating capacity there. He also explained that he was more familiar with the facilities in Landover. Sinatra aides angrily denied rumors that he chose Landover over the Kennedy Center because of a falling out he had with the Kennedy family.

Jet setter bickering aside, meanwhile, Prince Georgians are awaiting the gathering with a mix of awe, civic pride and down-home wonder.

"No man, I'm not invited. But hey, I'm happy those folks are coming here," says state Sen. Tommie Broadwater of nearby Hyattsville. "P.G.'s a part of the U.S., isn't it? I mean why shouldn't that party be here? Frankly, I'll be tickled to see them come through. To get to the Cap Centre they're gonna have to come through my district, which is predominantly black. "And when they do," says Broadwater, "I'll be out there waving."

Republican County Executive Hogan, who is invited to the bash, ardently defended the gathering and boasted that Prince George's is, in fact, a rather cultured place.

"We always get a bum rap. Look, 80 percent of the county is rural. We've got more farmland than any other local jurisdiction. We have more historical estates than Williamsburg. We have an opera, three symphonies, 22 theater groups and we've donated this barn for artists to work out of," Hogan declares. "Plus, we're the home of Air Force One. What could be more apropriate for a party of topnotch people than the Capital Centre?"

Johnny Carson will act as master of ceremonies for the event, which features, among the cast of entertainers, opera soprano Grace Bumbry, Charlton Heston, Dean Martin, Rich Little, Charley Pride, Donny and Marie Osmond, Jimmy Stewart, Bob Hope and Ben Vereen.

Pollin, who will also be there, said he was "pleased and honored that the Capital Centre was chosen for this prestigious event."

"Some very important people will be gathered under one roof here at an arena that is named after the national capital area," Pollin says. "No, it's not unusual. Carter's been here before for basketball games."

When asked whether tuxedos had ever graced the arena before, Pollin thought for moment then replied, "Sure. We've had horse shows where people wore white ties."

Still, this is going to be no mere horse show. Almost a dozen searchlights outside the arena will scan the skies as the top hats and long gowns arrive in stately limousines. Inside, amid a circus of red, white and blue streamers, a special ground-floor box has been erected for the Reagans and Bushes.

For the guests there are mixed drink concessions, instead of the usual beer fare, and oyster and clam bars instead of popcorn and hot dogs. Marylanders have been allotted 49 tickets to the event under a quota system used by the national Inaugural Committee.

"Yes, we did feel a little slighted. Maryland went for Carter, so what we got was mighty less than what Reagan states got," said state inaugural coordinator Barbara Taylor, a Potomac party activist. Other Prince Georgians invited to the celebration include Congresswoman Marjorie Holt, Mayor Audrey Scott of Bowie, county Republican committee chairwoman Barbara Anderson and an assortment of delegates who attended the Republican national convention.

Among the uninvited, meanwhile, there was a sense of nonchalance.

"Usually, we've got this arrangement with the Capital Centre where we give them room on our marquee to advertise their events in exchange for courtesy tickets," says Landover Mall's Dale Wright. "For this event they've somehow been strangely silent. All in all I think it's a good thing, you know, something P.G. folks can brag about. But the common people? Nah, it won't affect us in the slightest."