21 January
A list of events which occurred on the 21st of January.

Gary Perconte (Reuben Leder) is born.

Eurlyne Epper-Woldman is born.

Thomas Small is born.

Keno Deary is born.
The first Star Trek convention is held in New York City.

Cuauhtemoc Sanchez is born.

Fifty-first day of filming on . Fourth day of filming the Regula I cavern scenes.

 premieres in Sweden.

Kaylee Harwood is born.

Abraham Sofaer dies.

Final draft script for  is submitted.

Fourth day of filming on .

Fifth day of filming on .

Final draft script for  is submitted.

Third day of filming on .

 airs.
Fourth day of filming on .
Third day of filming on .

Bernie Bielawski dies.

Fifth day of filming on .
Thirtieth day of filming on .

Third day of filming on .

 airs.
Sixth day of filming on .

Steve Susskind dies.
 airs.
Fifth day of filming on .

IDW Publishing releases "Countdown, Number One", issue #1 of Star Trek: Countdown.

 airs.
 airs.

Unknown year
Leslie Hoffman, Doug Jung, and Lawrence Libor are born.

de:21. Januar
es:21 enero
it:21 gennaio
nl:21 januari
pt:21 de janeiro
ru:21 января
sv:21 januari