Warren M. Armstrong was born and raised in Dallas, Texas. He graduated from the University of Texas at Austin in 1998 with a Bachelor of Arts degree in History. In 2005, he obtained his law degree from St. Mary's School of Law where he was a member of the St. Mary's University School of Law External Advocacy Mock Trial Team, which competed and excelled in numerous mock trial competitions throughout the country. His success in these competitions earned him an induction into the prestigious National Order of Barristers.

Prior to returning to his hometown and joining Miller Weisbrod in 2009, Warren practiced law in Central and South Texas exclusively representing those persons injured by the wrongdoing of others. His current practice focuses primarily on construction accidents, motor vehicle collisions, trucking liability, and medical malpractice. He is a member of the State Bar of Texas, American Association for Justice; Texas Young Lawyers Association, Texas Trial Lawyers Association, and Dallas Trial Lawyers Association.