Trondheim (Norwegian pronunciation: [ˈtrɔnhæjm]), historically, Nidaros and Trondhjem, is a city and municipality in Sør-Trøndelag county, Norway. With a population of 176,348, it is the third most populous municipality in Norway and city in the country, although the fourth largest urban area. It is the administrative centre of Sør-Trøndelag county. Trondheim lies on the south shore of the Trondheimsfjord at the mouth of the river Nidelva. The city is dominated by the Norwegian University of Science and Technology (NTNU), SINTEF, St. Olavs University Hospital and other technology-oriented institutions.

The settlement was founded in 997 as a trading post, and was the capital of Norway during the Viking Age until 1217. From 1152 to 1537, the city was the seat of the Archdiocese of Nidaros; since it has remained the seat of the Diocese of Nidaros and the Nidaros Cathedral. It was incorporated in 1838. The current municipality dates from 1964, when Trondheim merged with Byneset, Leinstrand, Strinda and Tiller.

Lewis Trondheim (Laurent Chabosy), born 11 December 1964, is an extremely prolific French cartoonist and one of the founders (in 1990) of the independent publisher L'Association. Both his silent comic La Mouche and Kaput and Zösky have been made into animated cartoons. He explained his choice of pseudonym after the Norwegian city of Trondheim as follows: "As a last name I wanted to use a city's name, but Lewis Bordeaux or Lewis Toulouse didn't sound so good. Then I thought about this city, Trondheim… Maybe someday I will publish an album under my real name, in order to remain anonymous."

Lewis Trondheim was first known as the author of Les formidables aventures de Lapinot (later to be translated to English as The Spiffy Adventures of McConey). He invented the character in the late 1980s as a way to learn cartooning. The result was an initial 500 page graphic novel, Lapinot et les carottes de Patagonie. All the while, he was publishing short stories for the satirical French magazine Psikopat.