The answer to this question isn't as straightforward as it might at first seem, given the ever-increasing numbers of unemployed in the past couple of years and several of the companies' total number of employees not limited to Las Vegas alone. We're not as confident in the data we came up with as we usually are, but we did gather enough of it, all things considered, to give us a general picture of the situation.
MGM Mirage has by far the most employees, with upwards of 60,000-65,000 in Las Vegas, adding up CityCenter's 11,500-12,000, Bellagio's 8,000-8,500, MGM Grand's 7,500-8,000 range, Mandalay Bay's 7,500-8,000, Mirage and Luxor's 5,500-6,000 each, and Excalibur and Circus Circus with 4,500-5,000 each, plus Monte Carlo, New York-New York, and the smaller joints.
Second is, of course, Harrah's, with roughly 33,000-34,000. Caesars has 5,500-6,000, followed by Flamingo and Planet Hollywood (4,500-5,000 each), the Rio (4,000-4,500), Harrah's (3,500-4,000), and Bally's, Paris, and Imperial Palace (a total of 12,000), plus a thousand or so in the minor operations.
It looks like Las Vegas Sands employs 15,000 people at Palazzo and Venetian, which would make it third.
Beyond that, it gets even trickier. Wynn Resorts, for example, employs roughly 11,500 at Wynn Las Vegas and Encore, but is that more employees than Boyd Gaming has in Las Vegas alone? Hard to say, since Boyd has 16,000 employees nationwide, but we couldn't find a breakdown by region. It's a similar situation with Station Casinos, which has 15,000 employees nationwide. In Las Vegas, Wynn, Boyd, and Station are pretty close.
Then, near as we can tell, come the Las Vegas Hilton, Stratosphere and the Arizona Charlies, Riviera, Tropicana, Hard Rock, and Sahara.