Following graduation from law school, Bill joined the prestigious Boston law firm of Hale and Dorr, where he served as a trial assistant to Attorney James D. St. Clair, who was later appointed Counsel to President Nixon during the Watergate investigation. In 1970, Bill joined the law firm of his brother, F. Lee Bailey, as an associate.

In October 1992, Bill was appointed Co-Director of the Hurricane Insurance Information Center in Miami, Florida. The Center, established right after Hurricane Andrew wreaked its havoc on south Florida, was formed by seven national insurance trade insurance associations and twenty-two major insurance companies representing the largest segment of the property insurers in the state. Its mission was to inform and educate consumers and the media regarding insurance issues in the aftermath of the costliest natural disaster in U.S. History. The Center was closed at the end of September 1993.