Byåsen is a large neighborhood area in the city of Trondheim in Trøndelag county, Norway. It constitutes a large part of the city in the borough of Midtbyen. It encompasses a number of areas southwest of the main city centre. This includes all areas on the west side of the river Nidelva and north of Granåsen. This is mainly a residential area, with 32,136 residents as of January 1, 2003. Gråkallbanen tram line connects Byåsen to the city centre along with a number of bus routes as well as night time services by bus and tram in the weekends.

Midtbyen is a borough of the city of Trondheim in Trøndelag county, Norway. The borough comprises much of the city centre of downtown Trondheim plus part of the Bymarka rural areas to the west.