A three-mirror off-axis telescope was aligned by ray aberration
measurement and reverse optimization, which is the technique of creating a computer model of the telescope in its misaligned state. A set of Hartmann measurements were made at multiple field points and multiple focus planes. The Hartmann data were then used as targets for the ACCOS V lens design code that created via least squares optimization a misaligned model of the telescope to match the measurements. The physical telescope components were then moved opposite the misalignments of the model. The Hartmann pattern was generated using a five-hole Hartmann screen and measured by the use of a position-sensing, lateral-effect photodiode. Our results show this method is a viable tool for assisting in the alignment of optical systems.