The weakly bound complex Mg+-Ne is prepared in a pulsed nozzle/laser vaporization cluster source and the low-lying electronic states are studied with mass-selected photodissociation spectroscopy. The chromophore giving rise to the electronic spectrum is the 2P <-- S-2 atomic transition of Mg+. A (2)Sigma(+) ground state with (2)Sigma(+) and (2)Pi excited states is derived from this atomic transition. An unresolved continuum is observed to the blue of the atomic transition and is assigned to the B (2)Sigma(+) <-- X (2)Sigma(+) transition. Sharp structure to the red of the atomic transition is assigned to the vibrationally resolved A 2 Pi <-- X (2)Sigma(+) band system. Extrapolation of the Mg+ - Ne stretch progression in this system determines the excited-state dissociation energy to be D-0" = 1696 +/- 50 cm(-1), and an energetic cycle determines the ground-state value to be D-0" 95 +/- 50 cm(-1). The (2)Pi(r) <-- (2)Sigma(+) (9, 0) vibronic transition is rotationally resolved for both spin-orbit components, definitively assigning the two (2)Pi electronic states and yielding bond lengths of r(0)" 3.17 +/- 0.05 Angstrom in the ground state and r(9)' = 2.59 +/- 0.05 Angstrom in the excited state.