Kirk was born in February 1961 in Swindon, Wiltshire. He was raised in Scotland where he was brought up in Glasgow and attended Greenfaulds High School in Cumbernauld, North Lanarkshire. He studied for a BSc in Natural philosophy and Astronomy at the University of Glasgow before studying Part III of the Mathematical Tripos at the University of Cambridge. He was promoted to a PhD in General relativity at the University of Southampton.
