Parkinson’s disease (PD) remains a common neurodegenerative movement disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra. Undesirable plasma exposure and the blood-brain barrier (BBB) make the oral delivery of anti-Parkinsonism drugs challenging. Nanocrystals (NCs) can increase dissolution velocities and saturation solubility, improving oral bioavailability and brain uptake. In this study, Ginkgolide B (GB), a potent anti-Parkinsonism compound, was selected to verify the utility of NCs to effectively accumulate GB in both the blood and brain. Fabricated GB-NCs had an average size of 83.48 ± 1.77 nm, a PDI of 0.082 ± 0.006, a zeta potential of -19.25 ± 1.04 mV, a drug loading of 44.44%, and a rapid dissolution rate in vitro. GB-NCs exhibited enhanced cellular uptake and permeability relative to GB alone (p<0.01). The GB-NCs could protect neurons against cytotoxicity induced by 1-methyl-4-phenylpyridine (MPP+), and showed no toxicity in zebrafish. Fluorescent imaging in zebrafish indicated accumulation of the NCs in the gastrointestinal tract and brain. When orally administrated to rats, GB-NCs demonstrated more favorable pharmacokinetics than control group, with higher plasma and brain concentrations. Importantly, in a murine MPTP-induced PD model, GB-NCs treatment resulted in improved behavior, reduced dopamine deficiency, and elevated dopamine metabolite levels. Taken together, these data demonstrate that the fabrication of GB as small-sized NCs are an efficient formulation strategy to improve the oral bioavailability and brain delivery of PD therapies.