J. Alexandra Marriott was born and raised in Birmingham, England. She grew up watching her parents star in many amateur productions, but this was not her only inspiration for taking up acting. Another main influence was watching many West End musicals, in particular "Phantom of the Opera", which lead her to take up singing. She trained with an experienced singing coach for several years and entered many local singing competitions to much acclaim, gaining many placing's and distinctions. This naturally led Jo to join an amateur dramatic society which saw her perform in several productions, playing chorus and lead roles.

Joanne then enrolled at the Coventry Centre of Performing Arts on a two-year diploma course. During this time she also joined a local medieval re-enactment group performing historical shows, where she gained her first taste for sword fighting!

Re-enactment opened up film and television work for Jo with production companies making historical documentaries. Jo has portrayed a wide array of characters, which included roles such as Maid Marion, Joan of Arc as well a fully armoured knight on horseback.