Elementary particle interactions refer to the fundamental forces and reactions that occur between elementary particles, including strong, electromagnetic, weak, and gravitational interactions, which are described by quantum field theories such as the Standard Model of particle physics.

Elementary particles are the fundamental units of matter, which according to the Standard Model of particle physics, include quarks, leptons (such as electrons and neutrinos), and gauge bosons (such as photons and gluons) that constitute all known forms of matter and energy, with the exception of gravity.