This paper documents the design and performance of advanced reflective optical systems that have been developed for laboratory collimators. Each system is designed to meet the specific requirements of the end item test article or Unit Under Test (UUT). Four specific examples are cited and a brief description of each system is included. The Large Aperture Infrared Telescope Sensor Telescope (LAIRTS) was utilized as a laboratory collimator. This system is a four-mirror "Aft-Schmidt" configuration. The system is used off-axis to provide an unobscured aperture. M1 and M3, the large elements in the system, ,and M2 are spherical figured optics, while the M4 is a Schmidt corrector. This system provides a full 1 x 1 degree field-of-view with a flat field over a 22 inch aperture. Two reflective Schmidt configurations are reviewed. The first is a Wide Field-of-View (WFOV) collimator fabricated for McDonnell Douglas Astronautics Co. for the testing of their Mast Mounted Sight (MMS). It consists of a spherical primary, two flat mirrors, one, a fold mirror, and the second, a two-axis gimbal mounted scan mirror. The fourth element is the Schmidt corrector. The second Schmidt system is the ISTF collimator, also manufactured for McDonnell Douglas Company. This system has a large aperture, 97 cm diameter sphere, a 73 cm diameter fold flat, and a 46 cm diameter Schmidt corrector. The effective focal length is 3 meters with a 15 cm usable aperture at the unit under test through a full field-of-view of 5 degrees. The fourth system that is discussed is a wide field-of-view collimator that is presently being developed at SSG. This design consists of a three mirror off-axis configuration with a hyperbolic primary, a spherical secondary, and an oblate spheroid tertiary. This system is designed to meet a spot size specification of 150 microradians over a 12 degree field-of view.