Kate O'Mara (10 August 1939-30 March 2014) was an English actress who played the Rani in a number of stories. O'Mara's TV and film acting career dates back to the 1960s when she appeared in most of the major ITC productions such as Danger Man and The Saint, as well as The Avengers. She later also participated in a stage play based upon the Sydney Newman creation.
O'Mara made her Doctor Who debut as the renegade Time Lord the Rani in the 1985 story The Mark of the Rani. Between it and her second (and last regular) appearance in Time and the Rani, O'Mara made two dozen appearances on the American prime-time soap opera Dynasty, her best-known role internationally.
In 1993, O'Mara reprised the Rani for the charity special Dimensions in Time and in 2000 she played the role again for the BBV audio production, The Rani Reaps the Whirlwind.
O'Mara made occasional film and TV appearances in later years. In 2009 she was featured in the Talking About Regeneration featurette included on the DVD release of TV: The War Games.
She was the aunt of Tam Williams, the ex-wife of Jeremy Young, the sister-in-law of Michael and Martin Cochrane and the former sister-in-law of Simon Williams.