Denis James Evans (born 19 April 1951) is an Australian scientist who is an emeritus professor at the Australian National University and honorary professor at The University of Queensland.

Evans was elected as a fellow of the Australian Academy of Science in 1994, was awarded a Centenary Medal from the Australian Government in 2000, and was appointed as a Member (AM) in the General Division of the Order of Australia in 2016.

[2] Evans has won numerous awards, including the Rennie Memorial Medal of the Royal Australian Chemical Institute (1983),[3] the Frederick White Medal of the Australian Academy of Science (1990),[4] the H. G. Smith Medal of the Royal Australian Chemical Institute (2000),[5] the Boys-Rahman Lectureship of the Royal Society of Chemistry (2000),[6] the Moyal Medal for distinguished contributions to mathematics, physics or statistics of the Macquarie University (2004),[7] the David Craig Medal and Lecture of the Australian Academy of Science (2015)[8] and the Lennard-Jones Lectureship and Prize of the Royal Society of Chemistry (2019).

Evans is best known for his contributions to the statistical mechanics of nonequilibrium systems including the derivation and experimental validation of the Fluctuation theorem which is an extension of the Second Law of Thermodynamics, and his development of algorithms for nonequilibrium molecular dynamics simulations.

[10] Evans has over 350 publications on nonequilibrium statistical mechanics, dynamical systems theory as applied to bulk systems, irreversible thermodynamics, computer simulation algorithms for nonequilibrium systems, the relation of the intermolecular potential function to macroscopic fluid properties and molecular rheology.