About Us

M.C. O’Brien, Inc. is the oldest commercial real estate firm operating in Brooklyn, New York. Founded in 1909 by Michael C. O’Brien, Sr., M.C. O’Brien continues to be a family-run business by second and third generation family members. Our extraordinary history in the outer boroughs has brought us a wealth of experience in all property types – office, industrial, retail, investment.

At M.C O’Brien, Inc., our specialty is our clients. We believe in building long-term relationships with our clients by providing a high level of personal service and commitment to achieve their real estate goals. Because we are relationship-oriented and not transaction-oriented, our clients really benefit from our knowledge of the market, our involvement in our community, and our professional education in all aspects of our business.

M.C. O’Brien provides a full range of services for both real estate and business owners through our innovative operating platform and entrepreneurial culture.

Our Team

William P. O’Brien, SIOR
William P. O’Brien, SIOR

Davon Peters
Davon Peters

Jennifer Magalhaes
Jennifer Grosskopf

Elaine Olshausen
Loretta Visconte

Tom Tyne




M.C. O’Brien represents both buyers and sellers in commercial sales transactions. Our sales efforts center around a comprehensive marketing plan designed to expose your property to a targeted group of potential buyers. We’ll do our homework and put together a complete due diligence package for the property and then identify likely buyers and negotiate the best terms available in the current market conditions. Our buyer’s representation practices are client-oriented, too: we work with our client to learn about their needs and requirements and identify appropriate solutions. We’ll work with you through the entire process – start to finish – to ensure a smooth transaction.


Are you a landlord with vacant space to fill? A tenant looking for space? M. C. O’Brien Inc. represents both landlords and tenants by staying on top of market conditions and maintaining a current inventory of available property. If you need to lease space, we can let you know what’s out there. If you’re a landlord, we have the resources on hand to provide the market information you need to be competitive and add value to your property.

Property Management

M.C. O’Brien Inc. provides professional, comprehensive commercial property management services designed to add value to the investments of our clients. Our property management staff provides back office accounting services, maintains positive tenant relations, and oversees maintenance for the properties we manage. We recognize that proactive property management is an essential component of a strong real estate investment and we’re committed to providing it for our clients.