Marjorie Susan Monaghan (born March 19, 1964) is an American actress best known for her portrayal of Tessa Halloran (aka 'Number One') in the television series Babylon 5.
[5] Monaghan has performed in a number of science fiction television roles,[5][6] including starring as "JoJo" in Space Rangers[7][8] and an episode of Star Trek: Voyager.
[9] In 1999 she appeared in all eight episodes of Rescue 77 as a character named "Kathleen Ryan".
[10][11] Monaghan is best known for her appearances in 7 episodes of Babylon 5 as a character named "Number One" (Tessa Holloran).
[4][12] Monaghan started dating Grant Rosenberg in 2001 whom she later married on February 2, 2011.