Alion Science and Technology Corporation (pronounced: ah-LYE-un) is a technology solutions company delivering technical expertise and operational support to the United States Department of Defense, civilian government agencies and commercial customers. Alion was established as an employee owned company in 2002 from the purchase of the non-life science divisions of Illinois Institute of Technology Research Institute (IITRI) by the employees through direct contribution and loans. Alion was unable to continue to ^[-1] service its debt load and was purchased by private equity company Veritas Capital in August 2015.

Based in Tysons Corner, Virginia, Alion has 3300 employees at major offices, customer sites and laboratories worldwideand utilizes subcontractors whenever possible to keep their costs down.

One Alion product is the simulation software tool, Micro Saint Sharp.

On August 2016, Alion Science and Technology signed a potential five-year, $145 million contract to provide various support services to the U.S. Navy’s DDG 51 shipbuilding program. The contract covers ship production planning and engineering, systems engineering, combat systems test engineering, post delivery planning, configuration and data management and logistics services.