Lady Isobel Barnett (June 30, 1918 - October 20, 1980) was a British television personality, popular during the 1950s and 1960s.

Isobel Barnett was born in Aberdeen, Scotland. She appeared as an actress, but it was as a panellist on BBC television shows such as What's My Line that she became famous. Elegant and witty, she was regarded by audiences as the epitome of the British aristocracy.

When the more informal culture of the 1960s and 1970s brought an end to her television career, she descended into a reclusive and eccentric existence. In 1980, she was found guilty in court of a shoplifting offence, an event which briefly brought her back into the public eye. A few days later she was found dead in her home, having committed suicide.