Madulain is a municipality in the Maloja Region in the Swiss canton of the Grisons .

Madulain is first mentioned around 1137-39 as Madulene.

Guardaval Castle was built near the village of Madulain in the 13th century to administer the estates of the Bishop of Chur in the Upper Engadine. In 1409 the Bishop had to pledge the castle to the League of God's House to pay off some of his debts. Under the League, the castle was no longer an administrative center and was abandoned, falling into ruin.

Madulain has an area, (as of the 2004/09 survey) of 16.28 km2 (6.29 sq mi).