James Philip "Phil" Elliott FRS[1] (born 27 July 1929 in Gosport; died 21 October 2008 in Lewes) was a British theoretical nuclear physicist.

From 1951 he was in the theory department of the Atomic Energy Research Establishment in Harwell.

First he worked on neutron transport in reactors before turning to the core structure.

In cooperation with the head of the theory department Brian Flowers, fundamental work was carried out in the 1950s that helped to unite the shell model with collective models of the core structure.

In the 1980s he dealt with the interacting boson model and its justification in shell theory.