• The Grill: A Tucson institution right Downtown on Congress Street. It's popular with the after-hour bar crowds, but stays open even on those off-nights. The food is excellent, relatively cheap, and there's a full bar open until 2am. Live music some nights and the crowd is always interesting at the least. Don't expect a quiet, sit-down meal though, The Grill is notorious for its bad service and the drunks can get pretty rowdy and annoying. The food is very worth the trouble though, and you won't be able to do much better late at night in Tucson.
    Congress Street between Sixth and Scott Avenues ("next to Wig-O-Rama")
  • Shot In The Dark Cafe: Coffeehouse/Restaurant downtown on Broadway.   Open 24/7 as of October 1st, 2007.  They sell cigarettes and they have a well-ventilated Indoor Smoking Patio off to the side.  Good, inexpensive food.  Incredible espresso, very good coffee.  Between 5th and 6th avenue at the old Cafe Quebec location.
  • Broadway Cafe: Hidden non-chalantly behind trees and away from most of the late night frolicking spots is this '50's-style diner on its namesake Broadway. The place comes complete with fake jukeboxes on the tables, a lunch counter and the wait staff dressed up like extras on "Happy Days". The food is decent, but you can do better elsewhere, although maybe not at 3am on a Tuesday. The crowd gets a little weird on off-nights, especially late, but the staff are friendly (although not intrusive) and the food comes quickly.
    Broadway just east of Columbus.  Rumor has it they have cut their hours of operation back signifcantly.
  • Nico's Taco Shop: Nico's is not a rare thing in town, but the tiny Campbell/Fort Lowell location is the only one open 24 hours. For fast food Mexican, it doesn't get much better, and nothing beats a big plate of Nico's Special Fries at 3am after a night of drinking.
    on Campbell Avenue

  • Los Betos: There are several 24-hour drive-thru Los Betos, but the only 24-hour restaurant is the one by campus on Speedway at Park. This is coupled with a 24-hour Subway, so you really have your choice.
    Speedway at Park Avenue

  • Coffee X-Change: A local chain, Coffee X-Change has some excellent brew, a wide selection of teas, and has pastries and sandwiches. The Grant at Campbell location is the only 24-hour coffee house in Tucson. The down-side (and probably very deliberate) is that there is no free wi-fi, although you are welcome to pay a nominal fee for service. During exams, the place is jammed with students who shoot up Campbell to get wired and cram. Weekends also attracts an interesting crowd, but the place is usually empty by 4 or 5am.
    Grant at Campbell
  • The Broadway/Camino Seco location now has free wi-fi.  Maybe the others do also......  But THIS was unbelievable....today in spite of already having ordered coffee, iced tea and a sandwich it turned out there was a 25 cent charge for a cup of tap water.  Incredible!

  • The Chains: IHOP, Waffle House, Denny's and Subway (mentioned above) all have locations in Tucson open 24 hours.

  • Drive-Thrus: Taco Bell (Speedway at Campbell location), Jack-in-the-Box, Wendy's, Dunkin' Donuts (22nd Street location), Nico's, Los Betos and some Viva Burrito locations all have 24-hour drive-thrus.