Bill Gavin was born in East St. Louis, Illinois in 1955, and graduated cum laude with a Bachelor of Arts from St. Louis University in 1977. He went on to complete his Doctor of Jurisprudence and graduated cum laude from the St. Louis University School of Law in 1980, where he was a member of the honorary scholastic society, Order of the Woolsack, and a staff member of the St. Louis University Law Review.

He was admitted to the Illinois bar in 1980, the Missouri in 1982 and the Tennessee bar. He is licensed to practice law in Illinois, Missouri, Tennessee, the United States Courts of Appeals for the Seventh and Eighth Circuits, the United States District Courts for the Southern and Central Districts of Illinois, and the United States District Court for the Eastern District of Missouri.

Bill Gavin has extensive experience in the litigation of occupational disease claims of railroad employees, and has successfully litigated personal injury claims resulting from exposure to asbestos, diesel fumes, environmental tobacco smoke, creosote, benzene, welding fumes, solvents, cumulative trauma disorders, and noise.

As a result of his experience in railroad occupational disease claims, Bill Gavin has represented railroad workers in litigation in the courts of Illinois, Missouri, Tennessee, Colorado, Arkansas, Kentucky, California, Georgia, Florida, Iowa, Louisiana, and Mississippi. This litigation has included traumatic injury claims and occupational disease claims.

Personal injury attorney Bill Gavin is currently a member of the Illinois State Bar Association, Missouri Bar Association, Tennessee Bar Association, American Association for Justice (AAJ), Illinois Trial Lawyers Association, and The Missouri Association of Trial Attorneys. He served as a member of the Board of Directors of the St. Clair County Bar Association from 1984 to 1985.