By employing the two-color visible-ultraviolet (vis-UV) laser pulsed field ionization-photoelectron (PFI-PE) measurement, we have obtained rotationally selected and resolved photoelectron spectra for the MoO+(X-4 Sigma(-); nu(+) = 0, 1, and 2) and MoO+ (a(2)Delta(3/2,5/2);nu(+) = 0 and 1) cationic states. The unambiguous rotational assignments have made possible the determination of highly precise values for the band origin ifo nu(+)(00) = 60 147.9 +/- 0.8 cm(-1), rotation constant B-0(+) = 0.4546 +/- 0.0006 cm(-1), spin-spin coupling constant lambda = 26.454 +/- 0.017 cm(-1), and bond length r(e)(+) = 1.642 +/- 0.001 angstrom for the MoO+ (X-4 Sigma(-)) ground state; nu(+)(00) = 60 556.4 +/- 0.8 cm(-1), B-0(+) = 0.4711 +/- 0.0005 cm(-1), and r(0)(+) = 1.613 +/- 0.001 angstrom for the MoO+ (a(2)Delta(3/2)) excited state; and nu(+)(00) = 61 718.2 +/- 0.8 cm(-1), B-0(+) = 0.4695 +/- 0.0006 cm(-1), and r(0)(+) = 1.616 +/- 0.001 angstrom for the MoO+ (a(2)Delta(5/2)) excited state. The ionization energy (IE) for MoO is determined to be IE(MoO) = 60 095.1 +/- 0.8 cm(-1) [7.4508 +/- 0.0001 eV]. Furthermore, the vibrational constants are determined as omega(+)(e) = 1000 +/- 9 cm(-1) and omega(+)(e)x(e)(+) = 5 +/- 3 cm(-1) for MoO+(X-4 Sigma(-)); the vibration spacing Delta G(1/2) for MoO+(a(2)Delta(3/2)) is also measured as 1065 +/- 4 cm(-1). On the basis of the thermochemical cycle, together with the known IE(Mo) and the IE(MoO) determined in this study, the difference of 0 K bond dissociation energy for MoO+ and that for MoO is determined to be D-0(Mo+-O) - D-0(Mo-O) = IE(Mo) - IE(MoO) = -2890.8 +/- 0.9 cm(-1) [-0.3584 +/- 0.0001 eV]. The energetic and spectroscopic values determined here have been used for benchmarking calculations at the CCSDTQ/CBS level of theory. The CCSDTQ/CBS predictions, IE(MoO) = 7.457 eV, r(e)(+) = 1.651 angstrom, omega(+)(e) = 974 cm(-1), D-0(Mo-O) = 5.386, and D-0(Mo+-O) = 5.015 eV, are found to be in good agreement with the vis-UV PFI-PE measurements. We also recommend a set of equally reliable CCSDTQ/CBS thermochemical values for MoO and MoO+: Delta H-f0 degrees(MoO) = 383.7, Delta H-f298 degrees(MoO) = 384.0, Delta H-f0 degrees(MoO+) = 1103.2, and Delta H-f298 degrees(MoO+) = 1103.5 kJ mol(-1).