A discrete, time‐dependent energy deposition model is developed and applied to the study of high‐energy electron‐beam (100 eV–10 MeV) deposition in atomic oxygen. Secondary electron distributions are computed and observed to relax to steady‐state results. Characteristic relaxation times are shown. The loss function, mean energies per electron‐ion pair production, production efficiencies, and distribution functions are presented for a wide range of energies. The model uses the latest experimental and theoretical cross sections as input.