Meet The Team

Matthew B. LeBretton, Esq.


phone: 617-759-8917

Prior to founding Charles Street Strategies, a leading Boston- based public affairs firm, Mr. LeBretton served as Vice President of Public Affairs for New Balance and its family of brands for nearly a decade. In that role, Matt oversaw the vast expansion of New Balance’s property in Brighton, MA,  a public-private partnership widely lauded as a model for future such endeavors.  He also secured legislative and executive branch “wins” in procurement and  international trade.

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Dennis C. Callahan, Esq.


phone: 617-999-6583

Dennis brings his unique knowledge of land use, zoning, permitting, licensing, project management, master planning, public procurement, commercial and residential real estate development, and operations to Charles Street Strategies, fortified by a three-decade career in government agencies at several levels and a proven track record of solving complex problems. 

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Strategic Partnerships

Charles Street Strategies works with the following strategic partners:  

Charles Street Strategies is proud to call CMBG3 Law a strategic partner.  CMBG3 is the region’s largest owned and managed female owned law firm and can provide an array of support services for Charles Street Strategies and its clients.  For more information on CMBG3, please click here.


Mark Ciommo served as a Boston City Councilor from 2008 until 2020, and as Ways and Means chair from 2009 until 2020, overseeing a rich, complex era of urban development in the Allston-Brighton area. Councilor Ciommo is the longest-serving Ways and Means Chairman in the history of the City of Boston.

His tenure on the Council and the relationships he built in government lend Councilor Ciommo a level of insight into the oft-opaque workings of City Hall that has proved invaluable for clients. During his tenure as Ways and Means chair, Councilor Ciommo managed a $6.3 billion budget and the city achieved its highest-ever municipal bond rating of AAA. Working with the Allston-Brighton delegation, Councilor Ciommo negotiated the development of the historic Boston Landing commuter rail stop, collaborating among diverse community coalitions, interest groups, and grassroots activists to advance shared interests such as the implementation of bus and bike lanes.

Prior to winning elective office, Councilor Ciommo was the Executive Director of the Veronica B. Smith Multi-Service Center. Since retiring as the Dean of the Council, Councilor Ciommo has used his skills as a coalition-builder to help a range of clients involved in development and transportation projects.

Sean Morrissey founded Morrissey & Associates, LLC in 2007 to assist clients at the local, state, and federal level. Through individual and collaborative efforts, M&A offers strategic advice and counsel to a wide array of Fortune 500 companies with business interests in the Commonwealth.

Prior to founding M&A, Sean served as Vice President in the Boston office of Dutko Worldwide, a leading Washington, DC based public affairs and lobbying firm. While at Dutko, Sean was responsible for servicing the firm’s existing national clients and generating business development opportunities in New England.

Sean has significant Massachusetts public sector experience. As the Chief of Staff to former Massachusetts House Speaker Thomas M. Finneran (D-Boston), he served as the chief operating officer for the House of Representatives and counseled legislative leaders on issues ranging from administration and legislation to major public policy initiatives. In addition to his work with the Speaker, he served the House as Staff Director to the Committees on Taxation, Banks & Banking, and Criminal Justice under former Chairman James T. Brett (D-Boston).

Sean has also worked extensively with national legislative associations such as the National Conference of State Legislatures, the State Legislative Leaders’ Foundation, and the National Speakers’ Conference. As the primary contact for the Massachusetts House, Sean networked with legislative leaders and staff to promote best practices and advocate on the state and federal level. Given his tenure on Beacon Hill, he has a unique working knowledge of state legislatures and their leadership.

A veteran of many local and statewide campaigns, Sean remains active in Massachusetts politics. In addition to his many business and political affiliations, he has a keen interest in the human service field and serves as a member of the Board of Directors of The Arc of Massachusetts. For more information, please visit click here.