Grant O’Brien is in his second season at Purdue, joining Ryan Walters’ staff in West Lafayette and serving as the safeties coach following two seasons at Illinois.
In his first season with the Boilermakers, O’Brien made an immediate impact as he was named Our Coaching Network’s National Safeties Coach of the Year. O’Brien guided Dillon Thieneman to a record-breaking season in which the true freshman became an AP All-American (Third Team) and was awarded FWAA Defensive Freshman Player of the Year as well as Big Ten Freshman of the Year. Thieneman ranked third nationally in solo tackles and interceptions, while setting Purdue freshman records in both categories. He became Purdue's first All-America defensive back since Steve Jackson in 1990 (Gannett News Service) as well as the first AP All-America Boilermaker since College Football Hall of Famer Rod Woodson (1986). Under O’Brien’s tutelage, Thieneman (106) and fellow safety Sanoussi Kane (79) paced Purdue in tackles. Kane earned All-Big Ten Honorable Mention from the league’s coaches and media.
O’Brien’s final season in Champaign saw the Illini post an 8-4 record, holding opponents to 10 points or fewer in seven of those victories. He assisted Walters and defensive coordinator Kevin Kane as Illinois’ defense ranked in the nation’s Top 10 of 17 different categories, including the No. 1 scoring defense.
O'Brien helped coach one of the best defensive turnarounds in the nation in 2021, helping Illinois to a 5-7 record and ranked wins over No. 7 Penn State and No. 20 Minnesota. Illinois' scoring defense (31st from 97th), third down defense (31st from 89th), and total defense (52nd from 114th) all improved more than 50 spots in the nation rankings from 2020. The Illini made massive gains in the Big Ten defensive rankings, as well, jumping 9+ spots in scoring defense (4th from 14th), touchdowns allowed (t-3rd from 14th), yards allowed per game (5th from 14th), and passing yards allowed per game (1st from 10th).
O’Brien joined Illinois following three years at Missouri as a defensive quality control analyst. He helped Missouri earn bids to the 2020 Music City Bowl and the 2018 Liberty Bowl during his time in Columbia, primarily with the Tigers’ defensive backs.
O’Brien came to Missouri after stints at FIU (2017), Arizona Christian (2015-16), and Northern Arizona (2013-14). He was a part of two league titles at Arizona Christian in 2015 and 2016 as defensive coordinator, then helped FIU reach the Gasparilla Bowl in 2017 while working with the defensive line. O’Brien started at his alma mater Northern Arizona as the defensive graduate assistant, coaching the nickels/outside linebackers from 2013-14.
O’Brien played collegiately at Northern Arizona University, contributing as a defensive back and on special teams, following two seasons at Glendale Community College (Arizona). During his time at Glendale, he played quarterback and defensive back and was selected as a special teams captain, helping the Gauchos win back-to-back Valley of the Sun Bowls. O’Brien was an All-Academic selection at Northern Arizona University and helped the team to an FCS playoff berth in 2012. He graduated from Northern Arizona University in 2013 with a degree in secondary education history, before earning a master’s degree from NAU in educational leadership in 2015.
Grant O'Brien