Mr. Birnie joined Frederic Dorwart, Lawyers PLLC as a Member in 2024. Prior to joining the firm, Mr. Birnie was a partner in a regional law firm based in Tulsa, where he maintained a wide-ranging practice in corporate law, estate planning, and business litigation. He received his Juris Doctor from the Duke University School of Law in 2014, where he served as lead editor of the Duke Journal of Comparative & International Law. During law school, Austin served as an intern for the Honorable Sam Glasscock, Vice Chancellor of the Delaware Court of Chancery. He received a Bachelor of Arts in Economics and Philosophy from the University of Chicago in 2009.

Outside of his legal practice, Mr. Birnie is extensively involved in the Tulsa community. He has served on the Board of Directors of the Tulsa Opera since 2018, and was a member of the Board of Directors of the Tulsa County Bar Association from 2019 to 2024, where he served as Treasurer.