Margaret (Maggie) O. Costello


171 17th Street NW
Suite 2100
Atlanta, Georgia 30363


Maggie is an associate in the Corporate & Finance practice and a member of the Economic Development & Public Finance industry team. She focuses her practice on representing private and public companies in a variety of corporate and transactional matters, including mergers and acquisitions, corporate governance and operational matters, securities, finance, entity selection and formation, private offerings, and other matters.

In addition to transactional matters, Maggie has experience with general corporate contract review of various types of contracts. She also has experience assisting companies in securing economic development tax incentives and grants from various state agencies.

Maggie graduated with honors from Tulane University School of Law, receiving a Juris Doctor, where she served as the senior research editor of the Tulane Journal of International and Comparative Law. She also graduated from the A.B. Freeman School of Business, Tulane University, receiving a Master of Business Administration.


  • Tulane University School of Law, Juris Doctor,
    magna cum laude
    • Order of the Coif
    • Louisiana State Bar Association, Corporate and Business Law Section Award
    • CALI Award in Business Reorganization & Bankruptcy Procedure
  • Tulane University A.B. Freeman School of Business, Master of Business Administration
  • Georgia State University, Bachelor of Arts - Sociology,
    cum laude
  • Georgia State University, Bachelor of Arts - Political Science,
    cum laude
  • State of Georgia
    • American Bar Association
    • Atlanta Bar Association


  • Best Lawyers in America®: Ones To Watch, Mergers and Acquisitions Law, 2023-24