Elisabeth Sladen was born in Liverpool, England, and began her acting journey by attending a drama school for two years before joining the local repertory theatre in her hometown of Liverpool. It was during her time at the theatre that she met actor Brian Miller, with whom she would later marry after reconnecting in Manchester three years later.
Early in her television career, Sladen made appearances on various shows, including Coronation Street in 1960, Doomwatch in 1970, Some Mothers Do 'Ave 'Em in 1973, Public Eye in 1965, and Z Cars in 1962. Between 1974 and 1976, she landed a regular role on the iconic science fiction series Doctor Who, playing the beloved character Sarah Jane Smith. This role would prove to be a defining moment in her career, as she would go on to reprise the part in several spin-offs, including K-9 and Company in 1981, The Five Doctors in 1983, and the Doctor Who radio serials The Paradise of Death in 1993 and Doctor Who and the Ghosts of N-Space in 1996.
Sladen's work on television extended beyond her time on Doctor Who, with notable appearances on shows such as Stepping Stones in 1977, Send in the Girls in 1978, Take My Wife... in 1979, Gulliver in Lilliput in 1982, Alice in Wonderland in 1986, and Dempsey and Makepeace in 1985. In 1980, she appeared in the cinema film Silver Dream Racer.
After the birth of her daughter Sadie in 1985, Sladen took a step back from acting to focus on her role as a mother and housewife, making occasional television appearances, including on The Bill in 1984 and Peak Practice in 1993.
The fan reaction to her return as Sarah Jane Smith on Doctor Who in 2005 was overwhelming, leading to the production of a second Doctor Who spin-off, The Sarah Jane Adventures, which premiered in 2007 and was specifically created for Sladen.