About Andrew S. T.
Andrew S. T. Buchanan practices law in Illinois and Missouri. He earned his J.D. from Saint Louis University School of Law in 2002 after completing undergraduate studies in finance and banking at the University of Missouri–Columbia in 1999. Those years of formal training gave him a grounding in both legal doctrine and financial concepts. He brings that dual background to bear in his day-to-day work.
He began his legal career after law school, entering private practice in the region where he studied. Over time he advanced to a leadership role at Buchanan, Williams & O Brien, P.C., where he is a partner. The firm maintains a presence in the St. Louis and Joplin areas. His partnership reflects long experience inside a regional firm rather than a brief tenure at a national network.
Buchanan is admitted to practice in both Missouri and Illinois. That bi-state admission shapes the matters he handles. It means he regularly deals with questions of state law from two jurisdictions and the practical consequences of serving clients whose interests cross state lines. His undergraduate training in finance and banking also informs how he evaluates transactions and financial documents.
Colleagues describe him as steady and practical in approach. He prefers clear, direct writing in briefs and client communications. He has spent much of his career working inside a firm setting and has experience mentoring junior lawyers. That experience includes supervising casework and coordinating efforts across the firm’s offices. He is known within his firm for attention to detail and for managing the logistical aspects of multi-jurisdiction matters.
He continues to work at Buchanan, Williams & O Brien, P.C., splitting time between the firm’s St. Louis and Joplin offices. His current practice focuses on representing clients across Missouri and Illinois through the firm’s regional offices.
