Irvington is home to a number of members of the Unification Church, including several high-ranking families. There are several Church-owned estates and buildings located in Irvington and in the neighboring village of Tarrytown. Reverend Sun Myung Moon, the founder and, until his death in 2010, the spiritual leader of the church, had a large private estate of , the former Frederic Clark Sayles estate, on East Sunnyside Lane. As of 2012, the estate was still owned by the church, under its legal name "Holy Spirit Association for the Unification of World Christianity".