George Daniel Mostow (July 4, 1923 – April 4, 2017) was an American mathematician, renowned for his contributions to Lie theory.

[7] Mostow was elected to the National Academy of Sciences in 1974, served as the President of the American Mathematical Society in 1987 and 1988, and was a Trustee of the Institute for Advanced Study in Princeton, New Jersey from 1982 to 1992.

He was awarded the AMS Leroy P. Steele Prize for Seminal Contribution to Research in 1993 for his book Strong rigidity of locally symmetric spaces (1973).

[8] In 1993 he was awarded the American Mathematical Society's Leroy P. Steele Prize for Seminal Contribution to Research.

In 2013, he was awarded the Wolf Prize in Mathematics "for his fundamental and pioneering contribution to geometry and Lie group theory.