Susan Foreman is a fictional character in the British science fiction television series Doctor Who. She is played by actress Carole Ann Ford .

Susan is the granddaughter of the Time Lord known as the Doctor. Her last name of Foreman is an alias taken from the junkyard, owned by an "I.M. Foreman" at 76 Totter's Lane where she and the Doctor lived in during their time in London in 1963. Although it was never explicitly stated that she was the Doctor's biological granddaughter, they certainly treated each other as family. The production team of the programme did not originally intend for the pair to be related, but writer Anthony Coburn created the family tie as he was disturbed by the possible sexual connotations of an old man travelling alone with a teenaged girl.

The Doctor has explained that Susan and himself are exiles from their own people, and Susan was born in another time and on another planet (presumably Gallifrey). It is not known if Susan is her real name or another alias to make her appear more human. Susan claimed to have coined the name for the TARDIS, the Doctor's time machine, though later episodes seemed to indicate that it was a widely used term among Time Lords.

The Doctor and Susan had been already travelling for a time before they decided to settle in London to make repairs on the TARDIS. Susan began to attend the Coal Hill School in Shoreditch, where her advanced knowledge of history and science attracted the attention of schoolteachers Ian Chesterton and Barbara Wright. Attempting to solve the mystery of the "unearthly child", Chesterton and Wright followed Susan back to the junkyard, where they saw her entering what appeared to be a police box. When they investigated further, they discovered that the police box exterior hid the much larger interior of the TARDIS, and were whisked away on an adventure in time and space with the Doctor and Susan.

Susan continued to travel with the Doctor and her two teachers until the 1964 serial, The Dalek Invasion of Earth. During the events of that story, Susan fell in love with David Campbell, a freedom fighter in the year 2164. However, Susan felt that she had to stay with and take care of her grandfather. The Doctor, realizing that Susan was now a grown woman and deserved a future away from him, locked her out of the TARDIS and left after a tearful farewell. Carole Ann Ford had expressed a desire to leave the series as she felt the character of Susan was too limiting.

Ford reprised the role of Susan on television in the 20th anniversary special The Five Doctors, and played an alternate version of Susan in the Big Finish Productions Doctor Who Unbound audio plays Auld Mortality and A Storm of Angels. The character of Susan reappeared in the spin-off novel Legacy of the Daleks, which took place after the events of Dalek Invasion.

• Travelled from: 100,000 BC / An Unearthly Child to The Dalek Invasion of Earth