Mark Yarbrough was born in Austin, Texas, and has resided in Texas his entire life. He and his wife Jerry were high school sweethearts, and have been married for over 35 years. They had two children, Alex and Ashley.Mark attended undergraduate school at Abilene Christian University, earning his bachelor’s degree in Finance. After graduating, Mark worked for Dallas Federal/Bright Banc Savings as a loan counselor, personal banker, and branch manager.

While raising a family, Mark then went to law school at Texas Tech School of Law. Upon his graduation, Mark went to work in his father's law office. Mark jokingly called the firm Yarbrough & Father. In 1993, Mark was elected as the County & District Attorney of Lamb County, Texas. He has since been re-elected to serve a total of five terms, or 20 years. There, he has prosecuted sex offenders, capital murderers, and various other defendants.

Also in 1993, Mark was certified to teach the Walk Thru the Bible Old Testament seminars. In his spare time, Mark enjoys playing basketball and golf, and vacationing on the beaches of the Caribbean.