Brennan has represented employers in labor and employment matters for more than 10 years. Brennan represents and advises management in traditional labor issues such as labor relations, collective bargaining, union organizing, unfair labor practice proceedings before the National Labor Relations Board, and arbitrations.

In addition to his labor relations practice, Brennan also has extensive federal and state employment litigation experience involving the Equal Employment Opportunity laws, the Family and Medical Leave Act, Fair Labor Standards Act, and other federal and state employment laws. He also litigates covenant not to compete, trade secrets and related claims, and counsels employers in all facets of employee relations, including hiring, promotion, transfers, wage and hour matters, and affirmative action.

Brennan has been recognized by Super Lawyers in 2011, 2012, 2013, 2014 and 2015 as one of Georgia's “Rising Stars” in labor and employment law.