21 January

A list of events which occurred on the 21st of January.
;
:Gary Perconte (aka Reuben Leder) is born.
;
:Eurlyne Epper-Woldman is born.
;
:Thomas Small is born.
;
:The first Star Trek convention is held in New York City.
:Keno Deary is born.
;
: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 .
;
: airs.
:Fifth day of filming on .
:Steve Susskind dies.
;
:IDW Publishing releases "Countdown, Number One", issue #1 of Star Trek: Countdown.
;
: and both air.
;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