Vaughan Pratt (born April 12, 1944) is a Professor Emeritus at Stanford University, who was an early pioneer in the field of computer science.

Raised in Australia and educated at Knox Grammar School, where he was dux in 1961, Pratt attended Sydney University, where he completed his masters thesis in 1970, related to what is now known as natural language processing.

He then went to the United States, where he completed a Ph.D. thesis at Stanford University in only 20 months under the supervision of advisor Donald Knuth.

In 1976, he wrote an MIT AI Lab working paper about CGOL, an alternative syntax for MACLISP that he had designed and implemented based on his paradigm for top-down operator precedence parsing.

[10][11] Pratt was credited in a 1995 Byte magazine article for proposing that the Pentium FDIV bug might have worse consequences than either Intel or IBM was predicting at the time.