Career
She is known for her roles as Abbey in the British television series Misfits, Fedora in ITV's television series Jekyll and Hyde, and as Emelia Ricoletti in the Sherlock New Year special episode "The Abominable Bride". Raised in Tooting, South London, O'Keeffe trained at the Royal Welsh College of Music and Drama, and starred in a number of their stage productions. That same year, she had a part in the feature film Abraham's Point.
In 2010 and 2012, O'Keeffe played Sadie in both seasons of BBC Three's drama series Lip Service, about a group of lesbians living in Glasgow, Scotland. In 2012 and 2013 she played Abbey Smith in the lead ensemble for the final two seasons of E4 (TV channel)'s comedy-drama Misfits, about a group of young offenders in a London community service program who obtain supernatural powers. In 2013, O'Keeffe had roles in television episodes of Law & Order: UK and Peaky Blinders, and appeared in the feature films Filth and Svengali.
In 2015, she starred as Fedora, the side-kick and lover of the main antagonist in ITV's TV series, Jekyll and Hyde. In 2016, she appeared in the Sherlock special "The Abominable Bride" as Emelia Ricoletti, the "abominable bride" of the title.