James Marrow was born on 23 November 1966 in Bromborough, Wirral to John Williams Marrow and Mary Elizabeth Marrow. He attended Wirral Grammar School for Boys, then graduated with a 1st Class Honours Master of Arts (M.A) in Natural Sciences (Materials Science) from the University of Cambridge in 1988, where he was a student at Clare College, Cambridge before pursuing and completing a Doctor of Philosophy degree in 1991. During his PhD, he studied the Fatigue mechanisms in embrittled duplex stainless steel and was supervised by Julia King.