Midrange
Olympen / Lompa
One of the best known and largest places in east Oslo. Restaurant, beer Hall, nightclub and roof terrace. Recently refurbished, with classic Norwegian food.
Top end
Theatercaféen
Pretending to be a classic upmarket Wiener Café with a continental menu. What you get on the plate may only have a passing resemblence to the description on the menu. Staggeringly overpriced and excrutiatingly "culture-posh", you might just get better food from the Asian take-away in the removable kiosk across the street for a fraction of the price. However, being "the" classic Café in Oslo, the experience may just be worth it if your wallet is running thick.
Dinner
One of the finest Chinese restaurants in Europe. Specializes in the Szechuan and Cantonese kitchen. Their Peking Duck, which must be pre-ordered the day before, is a true feast.
Bølgen & Moi
Modern restaurant in the Frogner district. They've also got branches at Tjuvholmen and in Nydalen amongst other places.
Palace Grill
Highly recommended gourmet restaurant where the menu changes daily according to the chef's mood and available ingredients. A ten-course meal costs about NOK 850 per person. Only 23 seats and no reservations, but a good bar to while away the hours waiting for food.
Restaurant Oscarsgate
Always world-class food. Edging up for their second Michelin star, they still only hold one, while Oslo's finest chefs rave about them. Norway's finest restaurant by far. After the demise of Bagatelle, this tiny hole-in-the-wall gourmet retreat offer the finest in Nordic experimental cuisine, only rivalled by their "cousin" in Copenhagen, NOMA. The location seem modest but the experience is overwhelming. If you want to be in for a culinary treat of a lifetime in Oslo, here's the spot. Booking absolutely, absolutely essential.
Statholdergaarden
Arguably one of Oslo's finest seatings. Set in a beautiful 1800-century mansion, the combination of very friendly staff and extraordinary dishes makes it well worth its one star in the Michelin Guide. Not one to miss.
Hos Thea
A small place with outstanding food, small seasonal menu.
There are a lot of both expensive and cheap places to eat in Oslo. The cheapest restaurants are Asian restaurants which in many cases serve good food at low prices.Check the menus on the door.
Buy at least one 19NOK Hotdog. They are referred to as "grillpølse" or "kjempegrill" and they are great for keeping the low blood sugar troll at bay and to increase your weight! Other street snacks are also available throughout the city, but it's usually more expensive than in comparable cities elsewhere.
Aker Brygge tram 12, bus 21, 32, 33 or 54; stops Aker Brygge, Vika Atrium or Bryggetorget is a waterfront located south of the city hall. During summer the area is very noisy and vibrant. There are outdoor restaurants and bars almost everywhere. Be sure to get some tasty sea-food or whatever else you like to eat while you are there, or just enjoy your cold beer in the summer sea-breeze. Be advised that this is also the most expensive area in Oslo to dine or drink, so unless the weather is good, you can just as well stay indoors somewhere else.
Sven's, located near Vika Atrium, offers a fast food version of a traditional dietary staple - lutefisk. Sides include herring, pickled vegetables, and salted meats. Because of the amount of lye used to treat the food, be prepared to sign a waiver designating power of attorney upon entry. Closed Mondays.
You are also close to most of the restaurants, bars, or nightclubs located within the city center. A key reference point will be Stortingsgaten, running parallel to Karl Johans gate, both running eastwards from the Royal Palace this is also the main shopping area. While both of these streets have a few restaurants and nightclubs, most will be found in one of the side-streets running out from them, or parallel to them. It doesn't matter much where you start, you will find restaurants, bars, and nightclubs almost anywhere from the subway station Nationaltheatret at the west, to far beyond Oslo central railroad station on the east. There are several other areas, such as Grünerløkka tram 11-12-13 to Nybrua, Schous plass, Olaf Ryes plass or Birkelunden, MajorstuenT-bane, tram 11-12-19 or bus 20-22-25-45-46 to Majorstua, and Grønland T-bane to Grønland, bus 37 to Tøyengata or bus 60 to Norbygata that are worth checking out. Be advised that nearly all bars and nightclubs close at the same time, so if you want to get a taxi back to your hotel, try to leave a few minutes before the rush starts.