Tilly Masterson was the fictional vengeful sister of Jill Masterson, the late secretary and victim of Auric Goldfinger. Based on the literary character Tilly Masterton, who first appeared in the 1959 Ian Fleming novel Goldfinger, she was portrayed by Tania Mallet in its 1964 film adaptation of the same name. For the film both sisters had their surname changed from Masterton to Masterson.
Tilly plays a somewhat smaller role in the film version of the book. She is first introduced when James Bond is following Auric Goldfinger when he lands in Geneva. 007 is calmly driving along the road when Tilly speeds around a corner and beeps her horn, wanting to get past. Bond obliges and decides to pursue when he sees her drive past. However 007 restrains himself commenting "Discipline 007!". He stops on the edge of a hill when he notices Goldfinger has stopped below him.
Unknown to Bond, Tilly is trying to shoot Goldfinger, as revenge for his having killed her sister Jill, but misses completely, nearly hitting Bond in the process. She escapes in her car and 007 follows. After a short game of cat and mouse, Bond uses the tire shredder feature on his Aston Martin and shreds both Tilly's tires. 007 escorts her to the nearest garage, but she refuses any additional help.
Bond and Tilly Masterson meet up once more at Goldfinger's factory, where once again she is trying to kill Goldfinger. Bond stops her, but she accidentally sets off an alarm. Goldfinger's henchmen pursue Tilly and Bond in his Aston Martin, but by using its various features, he disposes of some of the following cars. However the road suddenly stops, forcing Tilly to run into the forest with 007 giving cover fire. Oddjob, Goldfinger's henchman and assassin, cast in his hat with a lined steel blade tab, and breaks the neck of her. When Bond catches up, she's already dead.
- Tilly is the second woman that Bond fails to protect from being murdered. The first was her sister, Jill.