A.J. Timothy Jull (born 18 December 1951) is a radiocarbon scientist at the University of Arizona's Accelerator Mass Spectrometer Laboratory, as well as Editor in Chief of Meteoritics & Planetary Science and Radiocarbon: An International Journal of Cosmogenic Isotope Research. Dr. Jull's work spans numerous disciplines, from radiocarbon dating the Shroud of Turin, to looking for signs of life in Martian meteorites.