Daniel Douglas Eley (1 October 1914 – 3 September 2015) was a British chemist and Professor of Physical Chemistry at the University of Nottingham.

Eley worked in a variety of areas including heterogeneous catalysis, organic semiconductors, molecular sieves, photochemistry and radiation chemistry, X-ray crystallography, equilibria in solution, colloids and interfaces and magnetic properties of materials.

He maintained links with industry, and money from ICI was used to set up a Centre for Colloid Science in the Chemistry Department.

He ran a large research group and published over 250 papers, some of which have been highly cited and a number of which are single author.

[5] Professor Eley worked with Sir Eric Rideal studying catalysts, especially the industrially-important reaction between hydrogen compounds containing carbon-carbon double bonds.