Background: There is limited data regarding the incidence, timing, and risk factors for ocular complications after proton radiation (RT) for childhood brain tumors. Methods: We performed a single-institution retrospective review of children treated with protons for brain tumors. Data abstracted included demographics, radiation details and ocular complications. Results: Of 81 children treated with protons for brain tumors, from 2010-18, 42 with ophthalmology data available, were included. Median age was 8.3 years (y) (0.8 – 20.6y) and median follow- was 2.1 years. Ocular complications were detected only in patients who received craniospinal irradiation (CSI). The incidence of ocular complications was 19% (8/42 patients) overall, and 62% (8/13) after craniospinal irradiation (CSI). Bilateral cataracts were detected at a median of 3.2 y post-CSI, with an incidence of 38% (5/13). Dry eyes were detected in 23% (3/13) of patients during or soon after CSI (0.04 and 0.7y post-RT). The median radiation dose (Gray RBE) to the lenses for patients with cataract was 29.3 Gy (19.41 – 38.07), and with dry eyes was 27.93 Gy (11.98 – 28.71) (mean doses to bilateral ocular structures). Multivariable analysis identified CSI as a significant risk factor for cataract and ocular complications overall. Conclusions: Children are at risk for cataract and dry eyes after proton CSI and need ophthalmology follow-up. Larger prospective studies are needed to validate our findings, identify risk factors, and formulate strategies for risk-mitigation. Longer follow-up is needed to determine the incidence of late ocular complications and consequent functional outcomes after cranial proton radiation.