Guy Flynn represents parties in all areas of commercial real estate investment, development, leasing and finance.

His clients include institutional investors, pension funds, developers, lenders, borrowers, underwriters, and other public and private business entities in various commercial transactions, including joint venture, acquisition and development, leasing, commercial finance, purchase and sale, workout, foreclosure, and syndication transactions. Guy also counsels clients with respect to land use regulation, taxation, environmental, corporate, and bankruptcy issues.

The respected English research firm Chambers & Partners lists Guy in Chambers USA, noting that he "is widely respected in the market," "is commended for his expertise in commercial real estate development and finance," is "very knowledgeable about commercial real estate tax issues and structures" and "adept at handling large transactions." Chambers has also noted "his involvement in a series of high-profile and high-value transactions in Maryland."

In March 2013, the Daily Record named Guy to its 2013 Influential Marylanders list. The list recognizes individuals who have made significant contributions in their fields and are regarded as leaders in Maryland. In November 2013, Guy was awarded a 2013 Leadership in Law Award from the Daily Record in recognition of his outstanding professional achievements, community service and mentoring within Maryland's legal community.

Repeatedly since 2007, Guy has been named a Maryland Super Lawyer by Law & Politics and Baltimore magazines. In June 2003, he was named a Legal Eagle and one of the Baltimore region's top lawyers by the Baltimore Business Journal. In June 2001, Guy was named one of Baltimore's "40 Most Successful Young Professionals" by Baltimore magazine. Based on peer reviews, Guy is listed in The Best Lawyers in America in the category of real estate.

Guy is past chairman of the Maryland State Bar Association (MSBA) Real Property Section Discussion Group, a monthly gathering of leading real estate lawyers in the state for discussion of topical matters. From 2001 until 2011, Guy served on MSBA's Real Property Section Council, which is the governing arm of MSBA's Real Property Section. Currently, Mr. Flynn serves on MSBA's Real Property Section Legislative Liaison Committee, which tracks and provides comment to legislation affecting real property interests in Maryland.

Guy is a member of the five-person Baltimore City Board of Ethics, where he has served since being appointed by Baltimore's mayor in June 2010. In addition, Guy is a vice-president and member of the Board of Trustees of the Walters Art Museum; a member of the Board of Trustees of the Baltimore Community Foundation; a member of the Boards of Directors of Maryland Legal Aid, Family & Children’s Services of Central Maryland, The Center for Urban Families and Baltimore Efficiency & Economy Foundation; a member of the Board of Governors of The Center Club (Baltimore’s premiere business club); and a member of the National Advisory Board of the Ron Brown Scholar Program.