Born Lucille Frances Ryan in the Mount Albert suburb of Auckland, New Zealand, Lawless is best known for playing the title character of the internationally successful television series Xena: Warrior Princess which ran from 1995 to 2001.
She is also known for the role of D'anna Biers (Number Three) on the re-imagined Battlestar Galactica. Most recently she appeared on the television series Spartacus: Blood and Sand and Spartacus: Gods of the Arena as Lucretia, Quintus Lentulus Batiatus' wife.
Lawless has a background in musical theater and appeared on Broadway in a production of Grease, as the character of Betty Rizzo, in 1997.
She went on to play another character, Lyla, in the first season episode "As Darkness Falls." But her key role was given to her when she was asked to play a villainous warrior woman named Xena in the episode "The Warrior Princess," which aired in March 1995.
To differentiate between Xena and the similar Lysia, Lawless' hair, naturally ash blond, was coloured black. Xena subsequently returned in two more episodes of the first season of Hercules, which portrayed her turn from villainess to good character.
The character was popular enough that a spin-off series was created for her. Xena: Warrior Princess debuted on 4 September 4,1995. Xena: Warrior Princess, like its parent program, was a hit, lasting six seasons, and Lawless became an international celebrity.