William P. O'Brien is a 1980 graduate of the University of Connecticut, where he received his Bachelor of Arts degree.  He attended New England School of Law, evening division, and received his J.D. degree in 1989, while working full-time as a claim supervisor in the Boston Field Office of the Travelers Insurance Company.

In 1989, Bill relocated to Connecticut, joined the Hartford Field Office of the Travelers where he continued to supervise personal injury claims involving automobile accidents, premises liability claims, construction accidents and defective products.  In 1991, he joined the Staff Counsel Offices of Aetna Property and Casualty as a trial attorney and, in 1996, with the merger of Travelers and Aetna, he joined the Staff Counsel Offices of the Travelers Property Casualty Company where he continued to litigate insurance defense matters.

In 2001, he joined Penny, Botticello & O'Brien as an associate and became a partner in 2004.  Since joining Penny, Botticello & O'Brien, Bill has been involved in civil litigation, including the representation of individuals who have been seriously injured by another's negligence.