Fiona Messer (SEY 2768 - unknown) was the younger sister of Linton Messer XI, and after his death, became the last surviving member of the Messer dynasty of United Empire of Earth (UEE) Imperators.
After working with her brother to usurp power from their father Ulysses, she engaged in seditious activities with elements inside the UEE to remove Linton from power and inherit his position. The intelligence she shared with the resistance group Tide helped spark the Anti-Messer revolution.
When the footage of the Massacre of Garron II leaked onto spectrum and the uprising began, Fiona noted in her personal log that it was spreading too quickly to control. Historians speculate she went on the run to avoid capture and the execution that awaited her brother. Her whereabouts after this point remain unknown.