Free electron

Free electron in physics may refer to:
 * Electron, as a free particle
 * Solvated electron
 * Charge carrier, as carriers of electric charge
 * Valence electron, as an outer shell electron that is associated with an atom
 * Valence and conduction bands, as a conduction band electron relative to the electronic band structure of a solid
 * Fermi gas, as a particle of a non-interacting electron gas
 * Free electron model, as a particle in the Drude-Sommerfeld model of metals
 * Free-electron laser, as a particle in the electron beam