Isabelle "Izzy" Sinclair, is a fictional character who appeared in the Doctor Who Magazine comic strip based on the long-running British science fiction television series Doctor Who. She was a companion of the Eighth Doctor. Izzy was born on October 12, 1979 (the same day that the first issue of Doctor Who Weekly was published). However, she did not know where she had been born, nor did she know who her biological parents were. She was adopted by Les and Sandra Sinclair, but because of her unknown ancestry chose to call herself Izzy S (for "Izzy Somebody") instead.