January 21 is the 21st day of the year. There are 345 days remaining until the end of the year.
January 21 is National Hug Day in the US.
- 1789 – The first American novel, The Power of Sympathy or the Triumph of Nature Founded in Truth, was printed in Boston, Massachusetts.
- 1908 – New York City passed the Sullivan Ordinance, making it illegal for women to smoke in public. The mayor vetoed it.
- 1915 – Kiwanis International was founded in Detroit, Michigan.
- 1976 – Commercial service of the Concorde began with the London to Bahrain and Paris to Rio routes.
- 1977 – President Jimmy Carter pardoned American Vietnam War draft evaders.
- 2008 – Marie Smith Jones, the last native speaker of the Eyak language died. She was born in 1918.