John Christopher Baillie Papaloizou FRS (born 1947) is a British theoretical physicist. Papaloizou is a professor at the Department of Applied Mathematics and Theoretical Physics (DAMTP) at the University of Cambridge. He works on the theory of accretion disks, with particular application to the formation of planets. He received his D.Phil. in 1972 from the University of Sussex under the supervision of Roger J. Tayler. The title of his thesis is The Vibrational Instability in Massive Stars. The asteroid 17063 Papaloizou is named after John Papaloizou.