William F. Wu was born on March 13, 1951, in Kansas City, Missouri, where his family lived until they moved three years later to Prairie Village, Kansas, a suburb in the Kansas City area. He attended Prairie School, where he was Student Council president in the sixth grade, Indian Hills Junior High, and Shawnee Mission East High School. He went to the University of Michigan, where his parents had met, and represented the third generation of UM students on his mother's side. He received an A.B. in East Asian Studies and an A.M. and Ph.D. in American Culture, all at UM, completing graduate school in 1979. During his time in grad school, he was active in East Wind, an Asian American student organization. In 1982, a revised version of his doctoral dissertation was published in hardback as The Yellow Peril: Chinese Americans in American Fiction, 1850 to 1940.
Bill sold a short story to a regional magazine in 1974, which was not considered a credit by the Science Fiction Writers of America. He attended the Clarion Writers Workshop at Michigan State University in the summer of 1974 and made his first professional sale in 1975, at age 24. He became a member of Science Fiction Writers of America in 1977 and was part of the SFWA Bulletin staff in 1981. From the fall of 1974 onward, he attended many science fiction conventions. Also during his time in grad school, he continued collecting comic books and wrote essays for comics fanzines as well as letters to comic books. Many of his letters were published, especially in Master of Kung-Fu when Doug Moench was the writer.
In the 1980s he married Diana G. Gallagher, who as Diana G. Wu won a Best Fan Artist Hugo Award. She went on to be a much-published author, primarily of Young Adult science fiction and fantasy. They divorced in 1990. In the 1990s, he bought a home in the El Mirage area of the high desert near Victorville, California, where he lived for nearly a decade.
After avoiding the necessity of a full-time job for many years, he became a copy editor in late 1997 at the Antelope Valley Press newspaper in Palmdale, California. He moved to Palmdale in 1999. He received a number of promotions while working at the AVP for nineteen-and-a-half years.
Bill married Fulian Tan in 2007. They lived in Palmdale until 2018, when they moved to Lakewood, California. Their son is Di (Alan) Wu Wang.