Benjamin Grayson Orr (1762–1822) was the fourth mayor of Washington, D.C., elected by the council of aldermen in 1817 and serving for two years.
Orr, probably born in Virginia, was a grocer in Georgetown – which in the early 19th century was a separate town from Washington. He moved into the city in 1812 and was elected an Alderman, but resigned one year later and became a supplier to U.S. Army brigades in Ohio and Michigan.
As mayor, Orr procured public improvements such as grading of the streets and established Washington's first volunteer fire companies, appropriating $1,000 for the purchase of four fire bells and procured apparatus for the companies. He also authorized a lottery to raise funds to build a penitentiary and city hall.
He died in 1822 and was buried in Congressional Cemetery.
Benjamin Orr Elementary School in Southeast Washington, D.C., which opened as an all-white school but in the 2016–17 school year was "97 percent black, 2 percent Hispanic and zero percent white," was named for him until 2018 when the predominantly black student body at Orr Elementary discovered the school was named for a slave owner and decided to rename the school for Lawrence E. Boone, the school's African-American principal from 1973 to 1996. The vote of the D.C. Council to change the name was unanimous.
Orr leased a slave for $250 to James Madison, Secretary of State of the United States at the time, according to the National Historical Publications and Records Commission.