Electron-impact ionization cross sections are essential parameters required in various plasma models. To provide self-consistent ionization cross sections in plasma modeling, an open database with tabular fitting parameters and an online web system are established in this work. There are 88 species composed of H, C, N, O, and F in this database. The Binary-Encounter-Bethe (BEB) model, the Deutsch-Märk (DM) model, and the combined model which consolidates the BEB and DM models are considered to obtain the atomic and molecular ionization cross sections. The input parameters of the above models for all the species are calculated according to the quantum chemical computation with the hybrid density functional theory method with the Austin–Petersson–Frisch functional including dispersion. The same methods and basis set ensure consistent ionization cross sections in the database. The average relative error between the calculated and experimental ionization potential is 1.84%. The average root-mean-square error of the fitted ionization cross sections is 1.81% with respect to the exact values predicted by the combined model. The online database can be accessed from the website http://plasma.mathboylinlin.com/db/cs/ion/.