Shadowcliff, also known as the Fellowship of Reconciliation Headquarters, is a historic home located at Upper Nyack, Rockland County, New York.

It was built in 1921, and is a large two-story, Classical Revival style masonry dwelling.

The 44-room residence features three porticoes, Palladian windows, and has a clay tile roof.

[2]: 3 It was listed on the National Register of Historic Places in 2014.

This article about a historic property or district in Rockland County, New York, that is listed on the National Register of Historic Places, is a stub.