Butler (Buck) Buchanan, III provides significant contributions to the leadership of the firm through his multiple roles as Managing Attorney of the Philadelphia office, Attorney Hiring Chair and Chair of the Diversity, Equity & Inclusion Committee. His years of experience in law practice and involvement and activity in numerous professional, industry and civic organizations provide the backdrop for his ability to successfully juggle these multiple positions.
As Managing Attorney, Buck oversees the operations, functions and initiatives of the firm's 130-attorney Philadelphia office. In his additional role as Attorney Hiring Chair, he is responsible for the recruitment and hiring of attorneys who join the firm. He also chairs the firm's Diversity, Equity & Inclusion Committee where he is charged, along with his colleagues, with ensuring that the firm's deep commitment to equal opportunity employment and advancement is brought to fruition.
Buck is a former Bucks County Deputy District Attorney, and he was engaged in private practice with a defense litigation firm before joining Marshall Dennehey's Professional Liability Department in 1999. In that capacity, he devoted a significant portion of his law practice to the defense of insurance agents and brokers, securities dealers and attorneys. He also handled environmental and insurance coverage matters, in addition to generic insurance defense work.
He was promoted to Hiring Chair in 2003 and to lead the Diversity, Equity & Inclusion Committee in 2009. During his tenure with the firm, he has also served two terms on Marshall Dennehey's Board of Directors.
In addition to his various duties for the firm, Buck is active in a number of legal and insurance organizations. He is currently a member of the House of Delegates of the American Bar Association. He is active in the Philadelphia Bar Association, where he has served as co-chair of the State-Civil Litigation Committee and as a member of the Commission on Judicial Selection and Retention. He is currently co-chair of the Large Law Firm Management Committee. He is a current member and a past-president of the Philadelphia Association of Defense Counsel and serves on the Board of Directors of the Insurance Society of Philadelphia. He is additionally a member of the Pennsylvania Defense Institute and the Defense Research Institute, where he has served on its Board of Directors.
Buck graduated from Millersville University, cum laude, in 1976 and earned his J.D. from the Duquesne University School of Law in 1979. Devoted to community and civic affairs, he is a former member of the Advisory Board of the Sisters of Saint Joseph Welcome Center and a former member of the Board of Directors of Mercy Vocational High School.
Honors & awards
AV Preeminent by Martindale-Hubbell
Pennsylvania Super Lawyers
2009-2021
2021 Renaissance Man Award, Philadelphia Chapter of the National Bar Association Women Lawyers Division
2021 Diversity Leader in Business Award, Philadelphia Business Journal
Thought Leadership
Liberty Mutual Insurance Names Marshall Dennehey External Law Firm Partner of the Year
October 24, 2025
Marshall Dennehey is honored to accept the External Law Firm Partner of the Year Award from Liberty Mutual Insurance.
On the Pulse...Our Philadelphia, Pennsylvania, Office
Philadelphia - Headquarters
December 1, 2022
As the managing attorney of the Philadelphia office of Marshall Dennehey, I am happy to have this opportunity to tell you about our corporate Defense Digest, Vol.
Marshall Dennehey Named a 2022 “Tipping the Scales” Firm by the Diversity & Flexibility Alliance
November 10, 2022
Marshall Dennehey has been named a 2022 “Tipping the Scales” law firm by the Diversity & Flexibility Alliance, as reported in the organization’s New Partner Report.
Marshall Dennehey Receives 2021 Champion of the Bar Award From The Philadelphia Bar Association
November 15, 2021
Marshall Dennehey Warner Coleman & Goggin was honored today with the 2021 Champion of the Bar Award from the Philadelphia Bar Association.
Classes/Seminars Taught
Best Practices for Retaining & Promoting Diverse Talent, Philadelphia Diversity Law Group's Diversity & Inclusion Symposium, November 2015
Barristers' Association of Philadelphia Leadership Academy, January 2015
Do the Right Thing! - Ethical Issues Arising in Litigation, Philadelphia Bar Association Bench-Bar Conference, October 2014
Women in the Profession Roundtable Discussion, participant, The Legal Intelligencer, April 2014
Technology and Law, DRI Annual Meeting
The Use of E-Mail and Electronic Documents Storage, DRI Annual Meeting
Electronic Discovery, DRI Seminar, Chicago, Illinois
Insurance Roundtable - Recent Developments Concerning Class Action Litigation, DRI, Chicago, Illinois
Insurance Coverage and Practice, DRI Seminar, New York, New York
Encouraging Ethics in Civility and Pre-Trial Practice, Pennsylvania Defense Institute, Philadelphia, PA
Professionalism and Civility: Is Civility Still the Rule in Civil Litigation Today? Atlantic City, New Jersey
Optimizing Brownfield Liability Recovery Through Insurance Settlement Strategies and Asset Management, Washington, D.C.
Lawyers' Professionalism - What Does It Mean in Everyday Practice? Philadelphia, PA
Seminars presented for Pennsylvania Institute of Certified Public Accountants, Pennsylvania Bar Institute, Greater Philadelphia Chamber of Commerce, National Insurance Industry Association
