At another celebration in the downtown Fremont Street entertainment district, 12 bands will play under a massive video canopy that will show the ball drop in New York's Time Square.
"The only thing that can top Las Vegas is Las Vegas on New Year's Eve," said Jacqueline Peterson of the Las Vegas Convention and Visitors Authority. "The city continues to evolve itself. We never run out of things to do."
Gaga's New Year's Eve concert at Park Theater at Park MGM casino-resort will be the third of her long-anticipated residency, which will debut Friday. Veteran Las Vegas performer Celine Dion will be at The Colosseum at Caesars Palace, and Maroon 5 will celebrate the holiday once again at the Mandalay Bay Events Center.
Stefani will take the stage at Zappos Theater at Planet Hollywood casino-resort as part of the residency she kicked off this year. Calvin Harris, The Chainsmokers and J. Cole are among those performing at nightclubs.
While Las Vegas is known as a place for last-minute trips, tourists who want to ring in 2019 there should act fast. Tourism officials expect 318,000 people to travel to Sin City for the holiday and nearly all the city's more than 147,000 hotel rooms to be booked.
"Now is the time to do it," Chris Baldizan, senior vice president of entertainment booking and development at MGM Resorts International, said about booking a trip for the holiday. But "we'll always find a spot for somebody."
Las Vegas police are planning an "all-hands-on-deck approach" to security, Clark County Sheriff Joe Lombardo said.
Authorities will deploy plainclothes officers, federal agents and police in and around the casino-resorts, along with rooftop snipers, Lombardo said.
New Year's Eve is worth an estimated $403 million to Las Vegas, according to the convention and visitors authority, which is responsible for promoting the destination.
In addition to concerts with tickets on sale for the general public, casino operators also host over-the-top private parties for their VIP guests.
Caesars Entertainment hosted nine of those last year, which included DJs, dancers, fireworks shows, thousands of bottles of champagne and performances by Katy Perry, Jennifer Lopez and other stars. Five hangover brunches were served the next morning.
Unlike the two previous years, New Year's Eve falls on a weekday. Casino operators say the Monday celebration is a positive because it gives people a reason to stay beyond a typical weekend trip.
"It just means that more of our guests are coming in even earlier to spend more days celebrating in this great tradition," said Chris Holdren, executive vice president and chief marketing officer for Caesars Entertainment. "So, they may come in, spend the weekend and extend it to encompass the great holiday."