US Post Office-Mount Vernon is a historic post office building located at Mount Vernon in Westchester County, New York, United States. It was built in 1915 and is one of a number of post offices designed by the Office of the Supervising Architect under direction of Oscar Wenderoth. It is a two to three story, symmetrical building faced with limestone in the Classical Revival style. It is composed of a five bay central section with flanking one bay recessed wings.
It was listed on the National Register of Historic Places in 1989.