Kaighn Smith Jr. has practiced federal Indian law with the Portland, Maine law firm, Drummond Woodsum MacMahon, for over 20 years, representing Indian tribes and their enterprises in the federal, state, and tribal courts and before federal administrative agencies across the country.  He has garnered a national reputation for his committed advocacy for tribal sovereignty, winning cases in a wide range of areas, including jurisdiction disputes, gaming matters, labor and employment relations, land-in-trust and environmental matters, and fishing and water rights.  Professor Smith is listed in national independent peer-based attorney guides, including Best Lawyers in America.  Chambers USA has awarded him it's highest national ranking for his Native American Law practice, listing him among the top practitioners (Band 1) in the United States.

Professor Smith regularly teaches courses in the field of federal Indian law.  In 2021, he served as the Distinguished Practitioner in Residence at Cornell Law School, where he designed and taught The Law and Colonization in Indian Country and supervised students on research and conference programing on Indigenous Nations and Climate Change. 

In addition to his teaching, Professor Smith regularly publishes articles in law journals and speaks at national conferences.  He is an elected member of the American Law Institute and, since 2012, has served as Associate Reporter in drafting the Restatement (Third) of the Law of American Indians, recently approved for publication by the ALI membership.  He is also the author of the leading treatise, Labor and Employment Law in Indian Country, (Native American Rights Fund, 2011) (336 pp), and is currently working on the next edition.