The First Harrison Gray Otis House is a historic house museum and National Historic Landmark at 141 Cambridge Street in the West End of Boston, Massachusetts.

It is notable as one of the earliest three-story brick houses that came to represent the Federal style of architecture, and its interiors show the influence of Robert Adam.

The house is now the headquarters of Historic New England, a regional preservation organization, and is open year-round for tours.

[2] The house is three stories tall, five bays wide, with elegant string courses.

The house underwent a careful restoration in 1960, overseen by Abbott Lowell Cummings.