Ertonn Chatelain begins his coaching career at St. Thomas University, following his playing career with the Bobcats from 2019-2022. During his senior year, Chatelain was part of a historic St. Thomas defense that helped the team to a 9-3 record—the most wins in program history at that time. The defense was ranked top in scoring defense, red zone defense, and sacks, with Chatelain playing a pivotal role in the defensive line unit's success.
After completing his playing career, Chatelain transitioned into coaching at his alma mater in 2023, starting as a defensive graduate assistant working with the defensive line. That season, St. Thomas made its first-ever appearance in the NAIA National Championship Playoff Series, with a stellar performance from the defensive line unit tallying 5 sacks in the first round win. During this successful campaign, Chatelain played a significant role in the development of All-Conference players Omilio Savage and Nicholas Engler with Nicholas Engler earning his first-ever AFCA 1st Team All-American honors. Savage led the conference with 7.5 sacks, while Engler finished second with 7. Under Chatelain’s guidance, the Bobcats' defense ranked sixth nationally in rushing defense with the defensive line accounting for 52  total tackles for loss over the season.
In 2024, Chatelain was promoted to being the defensive end’s coach, continuing to elevate the performance of the Bobcats’ defensive line. Under his leadership, the defensive ends accounted for 20.5 of the team’s 31.5 sacks, creating consistent pressure on opposing quarterbacks and disrupting the line of scrimmage. This played a key role in the secondary ranking second in the nation with 19 interceptions. Chatelain also coached Nicholas Engler to his second 1st Team AFCA All-American award while further cementing the dominance of the St. Thomas defense.
Chatelain’s experience as both a player and coach has made him a key asset to the St. Thomas University football program.
