- New Hampshire
- Maine
- Massachusetts

Sean is an associate in McLane Middleton’s Family Law Practice Group. His practice involves representing clients in New Hampshire, Maine, and Massachusetts.
Before joining McLane Middleton, Sean was a partner in a Maine law firm. He focused on various family issues, including parental rights and responsibilities, divorce, termination of parental rights, and adoption.
Sean received his LL.M. from The George Washington University Law School. He earned his J.D. from Roger Williams University School of Law. While in law school, Sean was the Vice President of the Student Bar Association and received the Feinstein Institute of Public Service Award for his work with the Navy. Sean received his B.A. from Plymouth State University, where he was a member of the school’s boxing club.
In his free time, Sean spends most of his days with his wife and daughters. He is also an assistant head coach for a local high school football team.
Admissions
Involvement
- Leadership Seacoast, Class of 2025
- Leadership Seacoast Admissions Committee
- New Hampshire Bar Association
- Maine Bar Association
- Massachusetts Bar Association
- NH Association of Justice
- DOVE Program
- George Washington University Law School Alumni Association
Recognitions
- Best Lawyers of America – Ones to Watch 2026
- Maine Supreme Judicial Court’s Katahdin Pro Bono Service Award, 2021, 2023, and 2024
- Aroostook Achievers Award (35 Under 35), 2019
Latest News
- 61 Attorneys from McLane Middleton Recognized in 2026 Best Lawyers in America® (August 21, 2025)
- Sean Leonard Graduates from Leadership Seacoast (June 12, 2025)
- Sean Leonard Accepted into Leadership Seacoast (November 21, 2024)
- Sean Leonard Honored by the 2024 Katahdin Counsel Recognition Program (November 7, 2024)
- Sean Leonard Honored by the 2023 Katahdin Counsel Recognition Program (January 11, 2024)
- McLane Middleton Adds Attorneys Sean Leonard and Madeline Lewis (July 25, 2023)