Kathryn Smith, also known as Kate Locke, Kady Cross, and Kate Cross, is a Canadian author. Smith's earliest novels were paranormal romances in an historical setting, written under the name Kathryn Smith. She then turned to writing steampunk for young adults as Kady Cross and steampunk romances as Kate Cross. The Immortal Empire series, set in an alternate steampunk London, was published as Kate Locke and categorised as urban fantasy. It is unclear which, if any, is her 'real' name, and which are nom de plumes. She and her husband, Steve, currently live in Connecticut, USA.