Benjamin Stanley Simmons (March 10, 1871 – September 8, 1931) was an American architect.

Born in Charles County, Maryland, in 1872, Simmons came as a child came to Washington, D.C., where he would later establish his career in architecture.^[1] He received his architecture degree at the University of Maryland, and continued his study at MIT.^[2] He started designing and building houses in the 1890s, before he moved on to bigger commissions.^[3] In 1902, the Evening Star described Simmons as "an architect who has added to the beauty and growth of this city."^[1][4]

He established himself as an extremely prolific architect, ultimately designing more than 280 buildings in the city.^[2] Simmons worked with every major developer, and appears to have had a particularly close working relationship with Lester A. Barr and later his son, John L. Barr, with whom he designed some of his best-known commissions.^[2] Simmons was versatile, designing a variety of building types including row houses, fraternal clubs, and commercial and institutional buildings. He seems to have had a proclivity for apartment buildings, of which he designed more than 60. Among his other works are the National Metropolitan Bank Building at 15th and G Streets NW (1905), the Elks Club at 919 H Street NW (1908, demolished); and the Fairfax Hotel at 21st and Massachusetts Avenue NW (1921).^[3] His earlier Hume School, built in 1891, is on the National Register of Historic Places, along with the National Metropolitan Bank Building, the Wyoming Apartments, and the Barr Building.^[5]

Although he never studied at the École des Beaux-Arts, Simmons became a student of the Beaux Arts tradition and the City Beautiful Movement. While his 19th-century speculative row houses reflect Victorian styles of architecture, his early 20th-century buildings are grander and more monumental structures that reflect a variety of academic styles inspired the City Beautiful movement, including the Classical Revival style and Renaissance Revival.^[2]

Simmons died in 1931 at 60. He was survived by a son, B. Stanley Jr., and 11 grandchildren.^[1] Many of his buildings were recognized in the late 20th century.