William C. "Bill" Mann (died August 13, 2004, aged 69) was a computer scientist and computational linguist, the originator of Rhetorical Structure Theory (RST) and a president of the Association for Computational Linguistics (1987–1988). He is especially well known for his work in text generation.
He received a Ph.D. in artificial intelligence and computer science at Carnegie Mellon University under Herbert Simon and Allen Newell.
From the mid-1970s until 1990, he was a researcher at the Information Sciences Institute of the University of Southern California. From 1990 to 1996, he was a consultant with the Summer Institute of Linguistics, based in Nairobi.