Ivan Sansom (born Prestatyn^{[citation needed]}) is a British palaeontologist, Senior Lecturer in Palaeobiology at the University of Birmingham. His research has focused primarily on the conodont palaeobiology and the early Palaeozoic radiation of vertebrates.^[1]

Sansom is an editor of the Journal of the Geological Society.^[2]

In 2001 Sansom was a recipient of the Palaeontological Association's Hodson Award, conferred on palaeontologists who have made a "notable early contribution to the science".^[3]

• Sansom, I. J., Smith, M. P., Armstrong, H. A. and Smith, M. M. 1992. Presence of the earliest vertebrate hard tissues in conodonts. Science 256: 1308-1311.]
• Sansom, I. J., Smith, M. P. and Smith, M. M. 1994. Dentine in conodonts. Nature 368: 591.
• Sansom, I. J., Smith, M. P. and Smith, M. M. 1996. Scales of thelodont and shark-like fishes from the Ordovician. Nature 379: 628-630.
• Smith, M. P., Sansom, I. J. and Repetski, J. E. 1996. Histology of the first fish. Nature 380: 702-704.
• Coates, M. I., Sequeira, S. E. K., Sansom, I. J. and Smith, M. M. 1998. Spines and tissues of ancient sharks. Nature 396: 729-730.
• Sansom, I. J., Donoghue, P. C. J. and Albanesi, G. L. 2005. Histology and affinity of the earliest armoured vertebrate. Biology Letters 2: 446-449.