Irina Kalashnikova Tezaur (born , also published as Irina Kalashnikova) is an American applied mathematician and a distinguished member of the technical staff at the Sandia National Laboratories. Her research concerns multiscale modeling and the computational fluid dynamics of compressible flow and of ice sheet dynamics.
Tezaur emigrated from Russia to the United States with her parents, a computer scientist and a physicist, in 1992, when she was eight years old. Initially, they lived in Detroit, Michigan, later moving to nearby West Bloomfield. She majored in mathematics at the University of Pennsylvania, graduating in 2006 with both a bachelor's and master's degree. She went to Stanford University for continued study in computational and mathematical engineering, and completed her Ph.D. in 2011 under the supervision of Charbel Farhat.
Her graduate studies also included work as a year-round technical intern at Sandia, in its Aerosciences Department, and when she finished her Ph.D. she became a senior member of the technical staff in Sandia's Computational Mathematics Department. She was promoted to principal member in 2015 and distinguished member in 2021.
Tezaur is a 2019 recipient of the Presidential Early Career Award for Scientists and Engineers, honored "for developing new, impactful mathematical methods and computer algorithms to enable real-time analysis, control and decision-making on computationally prohibitive problems relevant to the nuclear security mission and climate modeling".