The home of the Henry Clay Frick family from 1882–1905, this meticulously restored 22-room Italianate mansion features an impressive array of fine and decorative art objects purchased by the Fricks. An astonishing 93% of the artifacts in the house are original, making Clayton a home more than a house, and an eloquent evocation of the lives of the family who lived there. Henry Clay Frick's daughter, Helen, desired the house to become a museum after her death in the 1980s.

Grounds also contain a free Car and Carriage museum and an art museum showcasing Helen's personal collection.