The Single Aperture Large Telescope for Universe Studies (SALTUS) is a deployable space telescope designed to provide the astrophysics community with an extremely large far-infrared (far-IR) space observatory to explore our cosmic origins. The SALTUS observatory can observe thousands of faint astrophysical targets, including the first galaxies, protoplanetary disks in various evolutionary states, and a wide variety of solar system objects. The SALTUS design architecture utilizes radiatively cooled, 14-m diameter unobscured aperture, and cryogenic instruments to enable both high spectral and spatial resolution at unprecedented sensitivity over a wavelength range largely unavailable to any existing ground or space observatories. The unique SALTUS optical design, utilizing a large inflatable off-axis primary mirror, provides superb sensitivity, angular resolution, and imaging performance at far-IR wavelengths over a wide ±0.02 deg×0.02 deg field of view. SALTUS’ design, with its highly compact form factor, allows it to be readily stowed in available launch fairings and subsequently deployed in orbit.