Irene Ann Stegun (February 9, 1919 – January 27, 2008) was an American mathematician at the National Bureau of Standards (now the National Institute of Standards and Technology) who edited a classic book of mathematical tables called A Handbook of Mathematical Functions, widely known as Abramowitz and Stegun.
Stegun was born in Yonkers, New York. She began her mathematical career during the Second World War. After teaching mathematics at a Catholic school in New York, she joined the Planning Committee of the Mathematical Tables Project of the WPA. In that role, she learned the basics of numerical analysis from the committee's chair, Gertrude Blanch. While working at the Mathematics Tables Project, she completed a master's degree in mathematics at Columbia University.
In 1948, Stegun and a handful of other members of the Mathematical Tables Project moved to Washington, DC, where they set up the Computation Laboratory of the National Bureau of Standards. She eventually rose to assistant chief of the Computation Laboratory at NBS. In 1965, Stegun was awarded a Gold Medal from the Department of Commerce for her efforts in completing the project. She held the position of assistant chief of the Computing Lab until she became the interim director in 1965.