The diagnosis of concussion remains challenging, particularly in cases where several months have passed between a head injury and clinical assessment. Tracking multiple moving objects in three-dimensional (3D) space engages many of the same cognitive processes that are affected by concussion, a form of mild traumatic brain injury (mTBI), suggesting that tests of 3D multiple object tracking (3D-MOT) may be sensitive to post-concussion syndrome after a brain injury has occurred. To test this, we evaluated 3D-MOT performance (using NeuroTrackerTM) against Sports Concussion Assessment Tool results for cognition, balance, and symptom severity in a large sample (N = 457) of male and female participants between the ages of 6 to 73. 3D-MOT performance in subjects under age 13 was not impaired by a history of concussion, but was positively associated with cognition and balance. 3D-MOT performance in those 13 and older was negatively associated with concussion symptom severity, and positively associated with cognition and balance. 3D-MOT was selectively impaired in subjects with probable post-concussion syndrome (pPCS), defined using the 95th percentile of symptom severity for subjects with no history of concussion. A decision tree predicted concussion status with 95.2% overall test accuracy (91.1% sensitivity, 97.8% specificity) using concussion history, age, and 3D-MOT score. Individuals with a history of concussion in the past 37 days were predicted to have pPCS if they were age 35 or older, or if they were under age 35 but achieved scores below 1.2 on the 3D-MOT. These results demonstrate the potential of 3D-MOT for pPCS diagnosis, and highlight the increased vulnerability to concussion symptoms that comes with age.