Played by: Frazer Hines
A young Scottish piper from the 18th century brought in by The Doctor. Oblivious to the future and other alien worlds but never stands down. The last time he was with The Doctor was when he was taken by his people and put on trial. Jamie along with Zoe were both returned to their home times.
Played by: Deborah Watling
A young girl who along with her father were captured by Daleks. She was rescued by The Doctor and Jamie. She decided she couldn’t take much more danger so she decided to stay with a happy couple.
Played by: Wendy Padbury
A brainy young girl working on a space station called The Wheel which was later invaded by Cybermen. She felt so bored working on it that she decides to come along with The Doctor. She’s much smarter than a supercomputer. She along with Jamie were both returned to their homes with their memories modified.
Played by: Nicholas Courtney
First met The Doctor during the Yeti Invasion when he was a colonel. When The Doctor was exiled to earth, they met again except The Doctor has a new face and Lethbridge-Stewart is now a brigadier of his own army, UNIT (United Nations Intelligence Task force). Always brave no matter the situation.
Played by: Caroline John
Assistant to The Doctor. Always responds to him. Soon leaves to an academy at Cambridge.
Played by: Katy Manning
Cockney girl who gets hired to be The Doctor’s new assistant. Always manages to avoid dangers like The Master and others. Decides to leave with a scientist.
Played by Elizabeth Sladen
One of The Doctor’s most memorable companions. Another assistant brought to The Doctor. She decides she can’t stand being around him anymore, but before she could tell him, he tells her to leave because he’s been urgently called to Galifrey. She later receives a gift from The Doctor, K9 Mk3.
She returns in the new series with her trusted pet K9. She even has her own spin-off show: The Sarah Jane Adventures.
Played by: Ian Marter
Medical doctor for UNIT. He stumbles aboard with The Doctor and Sarah.
Played by: Louise Jameson
A savage warrior of the Sevateem. Encounters The Doctor and wonders where he goes. She is very feisty and savage like. She chooses to stay on Galifrey with K9.
Played by: John Leeson
A robotic canine computer designed to assist his master. Equipped with a stun gun. Always addresses his owners as master or mistress. Left on occasions but has been replaced with different versions. Stayed with Leela and replaced with Mk 2. Left with Romana and replaced with Mk 3 and given to Sarah Jane. Was destroyed and replaced with Mk. 4. Starred in a pilot episode titled, K9 and Company. Later stars in his own spin-off, K9.