Langenthal is a town and municipality located in the district of Oberaargau within the canton of Bern in Switzerland. While it is situated in this region, it is distinct from any location by that name in Germany.
The municipality has expanded through recent administrative mergers. On 1 January 2010, the municipality of Untersteckholz merged into Langenthal, followed by the merger of the former municipality of Obersteckholz on 1 January 2021.