Funny you should ask, as we're about to go to press with the 2016 edition of our Eating Las Vegas restaurant guide and one of the categories in the "Additional Recommendations" section, which follows on from the "Essential 50" restaurant list, just happens to be "Late-Night Dining," so we can vouch for what follows being up-to-date.
As a momentary aside, your point about Vegas being a 24/7 town used to be something of a misnomer when it came to dining. With the demise (somewhat) of the casino coffee shop, we've fielded more than a few QoDs on the subject, often citing the rule that casinos are legally required to offer dining around the clock. But that's not quite true: It's only those designated as a "resort-hotel," an entitlement that enables them to qualify for a "non-restricted" gaming license (covering an excess of 15 gaming machines, plus table games, and a race and sports book) that are required to offer both liquor from a bar and round-the-clock food of some sort (see QoD 6/6/2013 for more). And the food part doesn't need to be anything fancy, hence Vegas' famous tradition of "graveyard specials" - not exactly gourmet dining, but some cheap carbs to refuel on and/or soak up the booze.
The current writer recalls her previous incarnation as a documentary maker, a gig that often entails long, late-night hours, and the often futile quest, back in the late '90s, to find something other than fast food or biscuits and gravy anytime after midnight (or even prior). Most casino restaurants these days are still closed by 10 or 11 p.m., especially on week nights, and while I wasn't familiar with Chinatown, if I had been, it didn't offer the cornucopia of incredible -- in some cases world-class -- Pan-Asian dining options that it does today.
Now to some current after-hours hot spots, where you can find something delicious and nutritious to sate the beast in your belly -- and look out for imminent announcements re the release of Eating Las Vegas 2016, where you'll also find recommendations for the best of Chinatown and and Downtown, plus the best steakhouses, brunch spots, sushi joints, cocktail lounges, craft breweries, and a whole lot more besides.
Former showgirl and lieutenant governor Lorraine Hunt’s family has owned The Bootlegger since 1949. It’s changed locations over the years, but it still relies on the same tried-and-true family recipes. And you never know what Strip performers might stop by late at night to work out some new material on the dining-room stage. Open 24 hours, daily.
Las Vegas’ only 24-hour Capriotti’s sub shop is located across the street from the Hard Rock. Check out the signature "Bobbie" sandwich.
This old-school neighborhood Italian joint features classic fare (check the osso bucco) and nightly cabaret and has a video poker bar (currently closed for a remodel, but not for long) and free limo pick-up/drop-off to the Strip (remember to tip your driver!). Open until 5 a.m., daily (closed Tuesdays).
Two new modern Thai restaurants under the same ownership, both picks for "Best of Chinatown" and both open until 3 a.m. daily (closed Mondays)
A good Mexican restaurant connected to (but outside of) Sapphire Gentlemen's Club, open 24/7 daily.
Slingin’ the best hard-shell tacos in town, El Taco Felize is part of the loveably divey Money Plays bar. Open 24 hours, daily.
Thank the Asian clientele at Palace Station for a menu of authentic Chinese dishes, including rainbow jelly fish and hot and spicy duck feet (for the less-adventurous diner, there’s always the Mongolian beef and chicken chow mein). Also serves dim sum table-side in Asian Pit 8, and both options are available until 3 a.m. daily.
Open until 3 a.m. daily (aside from Sunday, when it's closed), the owner of this off-Strip steakhouse was also recently voted the best mixologist in the nation in the National 2016 Nightclub & Bar Awards (try the Moscow Mule).
Table-top grilled Korean BBQ, including all-you-can-eat, served 24/7 daily.
Hong Kong street food hits the Strip at one of Palazzo's newer eateries, with house specialties including Macau-style roasted pork belly, fried fish ball with curry, and King seafood Vietnamese noodle soup. Open until 1 a.m. weekdays, 3 a.m. Fri./Sat.
Another Chinatown favorite, open until 6 a.m. daily.
Located just around the corner from the LVA office, at Spring Mountain and Valley View, serving above-average Thai food, including some great lunch specials, and open until 5:30 a.m. daily.
Sushi & teppanyaki dining are the big draws at this eatery, plus a late-night happy hour. (Request Chef Tiger Woo for top R-rated entertainment value.) Open until 4 a.m., daily.
Located just off the casino floor at Venetian, next to the race and sports book, and serving large portions of noodle dishes, vegetarian specialties, rice and congee dishes, and soups. Open until 3 a.m., daily.
Gold Coast's popular Chinese spot specializes in dim sum and is open until 3 a.m. daily.
Planet Hollywood's new-ish pizza spot boasts the largest slices on the Boulevard, served by "pinup"-style waitresses—what more could you want from late-night munchies, center-Strip?! Open until 4 a.m. daily.
World-class Japanese fare (and recently featured by Anthony Bourdain) in the little strip mall at Spring Mountain and Decatur, which is replete with awesome eateries. Open until 3 a.m. daily.
Located on the second level of one of Chinatown's many strip malls, this place is a long-standing favorite of LVA and serves tapas-style Japanese dishes until 2:30 a.m. daily. Very popular with the Asian student crowd, thanks to the very reasonable prices.
Hip neighborhood joint, popular with a younger crowd, serving authentic Korean cuisine (sometimes with a twist). Good service, too, from an English-speaking staff. Open until 3 a.m. (Fri. & Sat., 4 a.m.; Sun., 2 a.m.).
Family-owned taverna serving authentic Portuguese cuisine, with a splash of Greek and a penchant for seafood. Check out the espetada beef, pork, or chicken skewers. Open until 3 a.m., daily.
From 11 p.m. nightly, when good boys and girls have gone to bed, The Wolf breaks out a late-night menu featuring everything from buttermilk pancakes and steak & eggs, to Jidori Half-Chicken and Linguine & Clams. Open until 6 a.m., daily (2:30 a.m. Tuesdays) inside MGM Grand.
We hope this list gives you some (late-night) food for thought. Actually, just some late-night food!