Claire Vallance attended Marlborough Girls College in Blenheim, New Zealand.  She then studied Chemistry, Physics, Mathematics, and Music at the University of Canterbury, where she completed a B.Sc.(hons) degree in 1995, graduating first in her year. She studied for a Ph.D. under the supervision of Peter Harland, working in gas-phase molecular dynamics, and graduated in early 1999. Upon completion of her studies, she returned to Oxford to take up a Violette and Samuel Glasstone Fellowship in the Physical and Theoretical Chemistry Laboratory and a Junior Research Fellowship at St. Catherines College.