Matt has spent his career as an advocate for the people of Baldwin and Mobile Counties. Matt was the former child victims prosecutor for Baldwin County handling all cases where children are the victims of sexual and/or physical abuse and previously worked with the Mobile County District Attorney's Office, for a combined nearly 12 years of prosecutorial experience. He currently works as an attorney with Davis & Fields, P.C. handling adoptions, mediations, civil litigation, probate law and business law cases.

During his time in office, Matt has been a champion for the people of Baldwin and Mobile Counties, working to help pass legislation that makes an impact for citizens in his district. He worked hard to locate a funding source to begin the creation of a Baldwin County Mental Health Court to help people with mental illnesses be able to seek treatment and counseling in lieu of jail time. True to his prosecutorial roots, Simpson has also been a tireless advocate for victims of crime, passing legislation that strengthened authorities' abilities to charge child sex crimes and helping shepherd legislation that would enhance penalties against people who committed homebuilder fraud.

Matt was born and raised in Mobile and attended Murphy High School. Matt went on to graduate from the University of Alabama and Cumberland School of Law. Matt was elected to the Student Honor Court by his fellow students at Cumberland. After graduation Matt and his wife, Marina, returned to Southwest Alabama and moved to Daphne.

In 2011, Matt was elected as Chairman of the Baldwin County Republican Party and served two terms. During that time the BCGOP made national headlines for hosting dinners that included speakers Andy Andrews, Dr. Ben Carson and Sarah Palin. Matt has also previously served as Chairman of the Baldwin County Young Republicans and was part of the recruitment committee that was able to bring the Young Republican National Convention to Mobile in 2013. Since 2008 Matt has been elected to serve on the Alabama Republican Party State Executive Committee and is currently the ALGOP Chairman for Congressional District 1. In 2017, Matt served as Chairman of the committee that created the ALGOP Code of Ethics for members.

Matt has also been very active in the community, serving on the Board of Directors for Fairhope/Point Clear Rotary Youth Center, The Family Center, and the Baldwin County Department of Human Resources. He is also currently the Chairman of the Baldwin County Personnel Board Grievance Committee. Matt is a graduate of the Federal Bureau of Investigations Mobile Division Citizen's Academy (2013) and Leadership Baldwin County (2015).

Matt's wife, Marina, is the Executive Director of the United Way of Baldwin County. She is on the Board of Directors for the United Ways of Alabama and the Eastern Shore Chamber of Commerce. She received the 2011 FDIC Chairman's Award for Excellence and was named to Mobile Bay's Top 40 Under 40 class of 2015.

Matt and Marina have two children, John Wallace (13) and Elizabeth (8). Matt is an elder at Coastal Church in Daphne.