Gillen was born in Jackson Mississippi, and moved to Marietta with his family when he was 6. He graduated from The University of Mississippi in 1995 with a B.A. in English and while there participated in the University Chorus, the Honors College and on the club soccer team. He is a graduate of the University of Georgia School of Law and while attending there, worked for the Athens-Clarke County Legal Aid and studied in London as part of an eight university consortium. Gillen began his legal work in immigration and litigation. He moved to the practice of residential real estate in 2002 and joined Ganek PC as an attorney in February of 2015. Gillen handles residential and commercial closings on behalf of lenders, buyers, sellers, builders, developers and investors. He has assisted agents and lenders with thousands of closings. Gillen continues to enjoy the challenges in the ever-changing field of real estate transactions and title work.
Gillen and his wife have three young children. They enjoy spending time together at sporting events and gathering with friends. Gillen is passionate about giving back and does volunteer work with Habitat for Humanity, Camp Fire and Camp Toccoa.