Katherine Cecil Thurston, born Kathleen Annie Josephine Madden (18 April 1874 – 5 September 1911), was an Irish novelist, best known for two political thrillers.

4 with her novel Max, the story of a young Russian princess, who flees disguised as a boy to the Montmartre Quarter of Paris, on the night before her arranged marriage.

Her 1908 novel The Fly on the Wheel, about illicit love, was described by writer Megan Nolan in 2022 as a "lost classic of Irish fiction".

Two more films were made using the American book title The Masquerader: in 1922 and then by the Samuel Goldwyn Company in 1933 as a "talkie" starring Ronald Colman.

Thurston had been dealing with epilepsy, and her blossoming career was cut short when she was found dead at the age of 37 in her hotel room in Cork.