Mahomes and Matthews have been together for many years and became engaged earlier this month.
"Just taking a small detour to the wedding," Matthews wrote on Twitter.
The 25-year-old Mahomes met Matthews, 25, while attending high school in Whitehouse, Texas. Mahomes went on to star at Texas Tech before entering the league in the 2017 NFL Draft.
Mahomes was the NFL's Most Valuable Player in his first season as a starter in 2018. In the 2019-20 campaign, he guided the Chiefs to their first Super Bowl win in 50 years.
Shortly before the start of this season, Mahomes -- who received the richest contract in U.S. team sports history over the summer when he inked a 10-year extension worth about $500 million -- obtained his championship ring and proposed to Matthews on the same day.
The Chiefs moved to 3-0 this season after Monday night's 34-20 victory over the Baltimore Ravens. Mahomes has nine touchdown passes and zero interceptions through three games.