Hobby played college football at the University of Tennessee under head coach Johnny Majors.
[5] In January 2017, the Jacksonville Jaguars hired Marion Hobby as defensive line coach.
[7] He missed the team's weeks 9 and 10 games against the Arizona Cardinals and Los Angeles Chargers on November 8 and 15, 2020, in accordance with COVID-19 protocols.
[8][9] On January 7, 2021, the Dolphins announced that Hobby and the team had mutually agreed to part ways.
[10] On January 16, 2021, the Cincinnati Bengals announced that Hobby would be their defensive line coach.