"Doomsday" is the thirteenth and final episode in the second series of the revival of the British science fiction television programme Doctor Who.

Set mainly in the One Canada Square skyscraper in Canary Wharf, the episode's plot consists mostly of the Daleks and Cybermen waging a global war, with humanity on the verge of extinction in the cataclysm.

The Tenth Doctor (David Tennant), the Tyler family, and Mickey Smith fight for their lives trying to reverse the situation.

It shared the revived series' highest Audience Appreciation rating of 89 with "The Parting of the Ways", "Silence in the Library", and "Forest of the Dead" until 28 June 2008—"The Stolen Earth" gained an AI rating of 91[1]—and is favoured by most critics for both the Dalek–Cyberman conflict and the farewell scene between the Doctor and Rose.

The Doctor explains that if he opens the breach and reverses it, anyone who has travelled between the two separate worlds will be pulled in, including Rose, Mickey and Pete.

Rose, her parents, and Mickey follow the voice to a remote bay in Norway where the Doctor sends a holographic message through one last small breach between universes.

[3][4] The two-part finale was originally going to take place in Cardiff on the time rift, which was the focus of the episodes "The Unquiet Dead" and "Boom Town".

When Torchwood was commissioned in 2005, Davies decided to base the spin-off in Cardiff and relocate "Army of Ghosts" and "Doomsday" to Canary Wharf in London.

[8][5][9] The last scene of "Doomsday", Catherine Tate's appearance in the TARDIS as Donna Noble (credited as "The Bride"), was filmed on 31 March during the wrap party.

[10] It is a favourite among fans and of executive producer Julie Gardner,[5] and is one of the reasons, along with Pappenheim's overall contribution and the "Song for Ten" from "The Christmas Invasion", that the soundtrack of both series was released several months later.

The companion episode of Doctor Who Confidential gained just over one million viewers, making it the second most watched programme on a non-terrestrial channel that week.

[16] The ratings for the episode were higher than the following World Cup match between Germany and Portugal, which had a million fewer viewers.

[21] The Stage commented that the Dalek–Cybermen conflict was the "only thing worth watching" at the weekend, overshadowing even the World Cup Final, and that the parting scene was "beautifully written and movingly played," with "not a dry eye in the universe".

[23] Stephen Brook of The Guardian thought that the episode was "a highpoint of the modern series, highly emotional, scary and genuinely exciting", while Rose's departure was "brilliantly handled".

He positively compared the episode's plot of a war between "the greatest monsters in the programme history" against the film Alien vs.

[28] In a 2014 poll by SFX, 90,000 readers voted the farewell scene between the Doctor and Rose as the greatest sci-fi moment ever.