Janson has been doing voiceover work for advertisements since she was a young child, adopting many different accents. Her first major television work was as Nicole Owen on Hollyoaks. Previous parts include the role of Heidi for a BBC radio drama. She left Hollyoaks in September 2006. Janson made her theatrical debut in Bad Blood at the Key Theatre. She made her West End debut in 2009, playing Louise in New Boy at Trafalgar Studios.
^"Soap star promises to return to home village - Entertainment - getsurrey". GetSurrey. 31 July 2007. Retrieved 7 November 2012. The actress attended Danes Hill School and regularly goes back there to watch the school plays. She said of her time there: "I loved it, I absolutely loved it." Ciara later went to Epsom College but did not go to university, choosing instead to focus on her acting career. "I don't know what I'd do if I wasn't an actress, probably English or psychology. I've never really given it a thought."