His father Jim is a British Telecom engineer He signed a professional contract with Kilmarnock at the age of 16. He made his senior debut for Kilmarnock on 18 May 2013, as they lost 3–1 at home to Street Mirren in a Scottish Premier League game.
His debut came at the age of 16 years and four months, making him Kilmarnock"s youngest player for 50 years.
On 3 October 2014, Kiltie signed for Scottish Championship club Queen of the South on a one-month loan. Kiltie has represented Scotland at every youth international level from under-15 to under-19.