Welcome to M.C. O'Brien, Inc's new website.

M. C. O'Brien, Inc. is currently the oldest commercial real estate firm operating in Brooklyn. The company was founded in 1909 by Michael C. O'Brien, Sr. and continues to be family-run by second and third generation family members. The company exclusively handles commercial property and is full service in that it has a management, appraisal and brokerage division.