Cook was born in New York City. His love of writing began in grade school, and in high school he wrote the occasional article for his schoolâ€™s newspaper. After high school, Cook spent time in the United States Navy and later worked his way through college, leaving little time for his writing endeavors. Cook began to write in earnest while working for General Motors at an auto assembly plant in a job which was â€œhard to learn, but involved almost no mental effortâ€, writing as many as three books per year. It was during this time that Cook wrote The Black Company, a novel published by Tor Fantasy in May 1984. It inaugurated a gritty fantasy series of the same name (or Chronicles of the Black Company) that follows an elite mercenary unit through several decades of its history.Â As of 2014, it comprises 10 novels published in three subseries plus recent short fiction. It has become something of a cult classic, especially among current and former members of the military.
Cook is also well known for his Garrett P.I. series, which tells the haphazard adventures of hardboiled detective Garrett, and his Dread Empire series, which highlights Cookâ€™s earlier published work. Cook is currently retired from his job at GM, living with his wife, Carol, in St. Louis, Missouri. Although he can now devote himself full-time to his writing career, he feels he was actually more productive while he was still employed at his old job.