Jæren is a traditional district in Rogaland county, Norway. The others districts in Rogaland are Dalane, Ryfylke, and Haugalandet. Jæren is one of the 15 districts that comprise Western Norway.
At about , Jæren is the largest flat lowland area in Norway, stretching from the municipality of Randaberg in the north to Hå in the south. It includes the whole Stavanger Peninsula and the mainland area at its base. The coast is flat compared to the rest of the very mountainous Norwegian coast, and it has sandy beaches along most of the coastline. The largest urban area in Jæren is the adjoining cities of Stavanger/Sandnes (pop. 210,874 in 2015).