Lierbyen is a village located in Norway that serves as the administrative center of Lier municipality within Buskerud county. It is situated along the Lierelva River in the valley of Lierdalen, which extends from Drammensfjord north toward Sylling near Tyrifjorden.
The village is positioned approximately 39 km from Oslo and about 8 km from Drammen, located off European route E18. Lierbyen forms part of a larger urban area that also includes the villages of Lier, Reistad, and Kjellstad. As of 2007, this combined urban area had a population of 4,233.