William R. O'Reilly, Jr.

William O'Reilly is a trusted advisor to numerous clients who rely on his strategic advice and guidance to help them navigate their most important real estate challenges. His practice focuses on all aspects of real estate law, including land use and development, private equity investment, financing, purchase, and sale and leasing.

For more than 35 years, Mr. O'Reilly has served as counsel for a broad range of clients, including institutional investors and lenders, foreign and domestic pension funds, domestic insurance companies and banks, developers, private equity investors, public REITs, Fortune 500 corporations and nonprofit institutions. He frequently advises clients on complex real estate challenges, and often collaborates with colleagues in WilmerHale's litigation, bankruptcy and environmental practices on these matters.

He has deep experience in the development and leasing of pharmaceutical and life science facilities, having recently represented several clients in complex laboratory developments. His experience also includes the representations of creditors and debtors in distressed real estate situations and workouts, as well as retailers and developers of multifamily housing, hotels, office and lab facilities in zoning, permitting and development.

Mr. O'Reilly is the author of Massachusetts Continuing Legal Education publications on Obtaining Zoning Permits and Approvals, Lease Drafting and Public/Private Real Estate Transactions.

Professional Activities

  • Trustee and Corporation Counsel, Boston's Museum of Science 
  • Trustee Emeritus, Tufts University
  • Past President, Board of Trustees, Beaver Country Day School
  • Director, Tufts University Hillel
  • Fellow, The American College of Real Estate Lawyers


    • Representation of the purchaser of a $725 million office and retail project in Greater Boston
    • Representation of a European financial institution in the restructuring and disposition of numerous properties and loans throughout the United States
    • Representation of a publicly traded REIT in its development, entitlement and leasing of 1,700,000 square feet of laboratory, office and residential space
    • Representation of the developers of hotel and residential towers in Boston
    • Representation of a multi-national pharmaceutical company in the development of research, development and laboratory buildings
    • Representation of a large NYSE retail company in land acquisitions, ground leases, entitlement and challenges to more than 100 new stores or store expansions
    • Representation and counseling of major educational and religious nonprofit institutions in dispositions, acquisitions and development of their key facilities
    • Representation of the developer of a planned 5 million square foot "smart growth" mixed use development in acquisitions, financings and entitlements
    • Representation of national multi-family developers in construction and financing of apartment and condominium developments
    • Representation of owners and developers of complex waterfront properties
    • Representation of pension fund advisors in portfolio-wide acquisitions and dispositions of properties throughout the United States
    • Representation of domestic and foreign lending institutions in workouts and lending on hotel, office, multi-family, condominium and retail properties


  • Consistently selected by his peers as one of the Best Lawyers in America (2005-2018) in the areas of real estate law and land use & zoning law
  • Recognized as a Massachusetts leader in the area of real estate in each edition of Chambers USA: America's Leading Lawyers for Business since 2004. In 2017, a source stated: "Terrific lawyer" William O'Reilly has a "strong reputation in the market" due to his provision of insightful counsel to a range of investors, lenders and developers. 
  • Recommended by The Legal 500 United States for his real estate practice
  • Endorsed in the real estate practice area for Massachusetts in the 2009/2010 PLC Cross-Border Handbook
  • Named one of Boston Magazine's "New England Super Lawyers" (formerly "Massachusetts Super Lawyers") in real estate each year since 2004

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