1961

April

 * 12 - Yuri Gagarin of the Soviet Union became the first human to travel into space, at least officially. (DW: The Seeds of Death)

Unknown dates

 * UNIT's predecessor, Great Britain's Intrusion Countermeasures Group was formed. Group leader Ian Gilmore begins training his men (MA: Who Killed Kennedy).
 * Peter Tracey was born (KAC: A Girl's Best Friend).

January

 * 7 - The Avengers debuted on British television. The series was devised by Sydney Newman, who next went on to create Doctor Who. During its run (which would last until 1969), the series played host to many guest actors who also appeared on Doctor Who, and many Doctor Who scriptwriters also wrote for The Avengers, including Terrance Dicks and Malcolm Hulke.
 * 12 - Sean Blowers was born.

February

 * 19 - Susan Baker was born.

April

 * 3 - Edward Highmore was born.
 * 25 - Cyril Nri was born in Nigeria.

May

 * 17 - Corey Johnson, who played Henry van Statten in DW: Dalek, was born in America.
 * 20 - Owen Teale was born.

September

 * 7 - Jamie Bradley was born.

October

 * 3 - A for Andromeda debuts on the BBC. This seven-part science fiction serial was considered a prime inspiration for the BBC considering the development of an ongoing serialised science fiction series, which eventually becomes Doctor Who.

November

 * 18 - Steven Moffat, the writer and Doctor Who Executive Producer and head writer was born in Paisley, Scotland.
 * 28 - Martin Clunes was born.

December

 * 12 - Sarah Sutton, who played companion Nyssa, was born.
 * 19 - Matthew Waterhouse, who played companion Adric, was born at Hertford, England, UK.

Unknown dates

 * David J. Howe was born.