In physics, a Dirac field is a fermionic field (usually a quantized field, as usual in quantum field theory) associated with spin 1/2 fermions such as the electron or muon.

The Dirac field transforms as the unconstrained spinor, and it satisfies the Dirac equation. The usual free Lagrangian for the Dirac field is

The Dirac fields are important components of Quantum electrodynamics and the Standard model.

A Dirac field is equivalent to two Majorana fields with the same mass.

A massless Dirac field is equivalent to two (massless) Weyl fields .