A compact, quantitative model of the distribution of charged particles between 1 eV and several MeV in the Jovian magnetosphere is presented. The model is based primarily on in situ data returned by experiments on the Pioneer and Voyager spacecraft, supplemented where necessary by earth-based observations and theoretical considerations. Thermal plasma parameters, notably convection speed, number density, and characteristic energy, are specified as functions of position for electrons and several ion species (H+, O+, O++, S+, S++, S+++, and Na+). At intermediate energy the electron and proton populations are modeled using kappa distributions, which join smoothly onto the radiation belt spectra at high energies (E>100 keV). At these energies the radiation belt intensity spectra include angular distributions for energetic electrons inside 16 RJ and protons inside 12 RJ. Major features of the magnetic field, thermal plasma, and trapped particle distributions are modeled, such as ring and satellite absorption signatures and corotational flow within the lo plasma torus and the current disk. Within each plasma region the model results are compared with observed spectra, showing that the model represents the data typically to within a factor of 2¿1 except where time variations, neglected in the model, are known to be significant. Several practical applications of the model to spacecraft near Jupiter are illustrated with sample results from radiation analyses and electrostatic charging calculations.