January 18 is the 18th day of the year. There are 348 days remaining until the end of the year.
- 1778 – James Cook was the first known European to visit the Hawaiian Islands, which he named the Sandwich Islands.
- 1788 – The first elements of the first fleet carrying 736 convicts from England to Australia arrived at Botany Bay.
- 1813 – Joseph Glidden, American farmer who patented barbed wire, was born. He died in 1906.
- 1911 – Eugene Ely landed on the deck of the USS Pennsylvania stationed in the San Francisco harbor, the first time an aircraft landed on a ship.
- 1943 – The first uprising of the Jews in the Warsaw Ghetto.
- 1944 – The Metropolitan Opera House in New York City hosted a jazz concert for the first time. The performers were Louis Armstrong, Benny Goodman, Lionel Hampton, Artie Shaw, Roy Eldridge, and Jack Teagarden.
- 1993 – Martin Luther King, Jr. Day was officially observed for the first time in all 50 states.
- 1997 – Boerge Ousland of Norway became the first person to cross Antarctica alone and unaided.