Valea lui Mihai (Romanian pronunciation: [ˈvale̯a luj miˈhaj]; Hungarian: Érmihályfalva) is a town in Bihor County, Crișana, Romania.

It is crossed by national road DN19 [ro] (on this segment, part of European route E671), which runs from Oradea all the way to Sighetu Marmației, on the border with Ukraine.

Valea lui Mihai officially became part of the territory ceded to the Kingdom of Romania in June 1920 under the terms of the Treaty of Trianon.

After the administrative unification law in 1925, the town became the seat of plasa Valea lui Mihai in Sălaj County.

In August 1940, under the auspices of Nazi Germany, which imposed the Second Vienna Award, Hungary retook the territory of Northern Transylvania (which included Valea lui Mihai) from Romania.

Towards the end of World War II, however, the town was taken back from Hungarian and German troops by Romanian and Soviet forces in October 1944, during the initial stages of the Battle of Debrecen; it became again part of Romania in March 1945.