Torchwood are a team of alien investigators, set up by Queen Victoria in 1879. There are 4 known Torchwood's around the British Isles.
 Torchwood 1
The main Torchwood, disguised as Canary Wharf appeared in prior to Army of Ghosts and Doomsday. It was in the middle of the Battle of Canary Wharf and was destroyed there and then. It was led by Yvonne Hartman before her upgrade to Cyberform.
Torchwood 1 had 'enough money' to build a skyscraper, capable of reaching a void ship. However, they realised the void ship was 'empty'. It had no mass, no size - it was a blank spot on Torchwood's computers. However, by tampering with the void sphere, 'ghosts' started leaking through into our world. When the tear became big enough, the ghosts revealed themselves - to be Cybermen, traveling from Pete's World to ours. After The Doctor questioned them, they revealed they did not break down the barriers - the void ship did, the Cybermen merely followed it. In a locked basement containing Rajesh Singh, Mickey Smith and Rose Tyler, the void ship opened - to reveal 4 Daleks, known as the Cult of Skaro.
 Torchwood 2
Based in Glasgow, Scotland and is said to be just offices. Captain Jack states it is ran by 'a very strange man'. It is unknown whether it is the same building as seen in Tooth & Claw. Torchwood two disbanded at some point prior to the 456 crisis in Children of Earth
 Torchwood 3
The main base of the torchwood currently in operation, and the only known base that is still active. It is led by Jack Harkness and has employed Gwen Cooper, Owen Harper, Toshiko Sato, Ianto Jones as their main team. Martha Jones in the past has helped at this Torchwood base.
 Torchwood Vehicle
The Torchwood vehicle is a largely converted and armoured, black Range Rover with tinted windows and blue lights running along the pillars. The license plate is a non-standard plate, that is usually found on military vehicles. CF06FDU is the plate number, which means it was registered in Cardiff during the period of 2006, in the first episode of Torchwood the plates when checked by Gwen and came up as unregistered. It contains computers that can connect to the Torchwood Hub and to various other databases. All the main characters have driven the vehicle.
 Torchwood 4
Torchwood 4 is said to be missing, and will turn up sooner or later
 References to Torchwood
- Bad Wolf - the answer to one of the Anne-Droids question was 'the Torchwood institute'.
- Tooth & Claw - The house where most of the episode takes place is called Torchwood House.
- School Reunion - There is a ban on Mickey's computer stating 'UNAUTHORIZED ACCESS - TORCHWOOD'.
- The Idiot's Lantern - When The Doctor is being questioned, the Chief Inspector references it.
- Fear Her - Torchwood is spoken over the Olympic 2012 broadcast.