Østerdal Billag is a Norwegian bus operator operating in Østerdalen in Innlandet.
The company also operates in cooperates with Gauldal Billag on a NOR-WAY express bus between Trondheim and Oslo.
The company has its headquarters in Tynset.
The company was founded in 1973 as a merger between 23 local bus companies and is owned by Gauldal Billag.
This transport corporation-related article is a stub.