Samuel Nicholas Smallwood (5 September 1772 – September 30, 1824) was the fifth and seventh mayor of Washington, D.C. and was the first popularly elected mayor of the city. Appointed to a one-year term in 1819, Smallwood was elected the following year to a two-year term, which he served from 1820–1822. He then was re-elected in 1824 but served only three months of his second term before dying at the age of 52.