Matt O'Donnell joined the Miami Dolphins as a defensive assistant in 2024 and was promoted to assistant linebackers coach in 2025.

Matt O'Donnell joined the Miami Dolphins as a defensive assistant in 2024 and was promoted to assistant linebackers coach in 2025.

The 2025 season marks O'Donnell's fifth year as an NFL coach, primarily working with the defense. He also has nine years of experience at the collegiate level.

In 2024, O'Donnell joined the defensive staff under first-year defensive coordinator Anthony Weaver. Despite a new scheme, Miami's defense bettered their top-10 finish in 2023 and finished fourth in the NFL in total defense in 2024, holding opponents to an average of 314.4 yards per game. It was the team's first top-five finish in total defense since 2006.

The run defense excelled, holding opponents to 103.7 rushing yards per game which was good for ninth in the league. Miami was also the only team to not allow a 100-yard rusher in 2024. In goal-to-go and red zone situations, Miami's defense also shined, ranking second in goal-to-go efficiency (60.0 percent) and fourth in red zone efficiency (49.1 percent).

Prior to joining the Dolphins, O'Donnell spent two seasons (2022-23) on the coaching staff at Brown. O'Donnell served as cornerbacks coach in 2022, before being promoted to recruiting coordinator/defensive line coach at his alma mater in 2023.

O'Donnell was responsible for recruitment efforts in Iowa, Kansas, Nebraska, North Carolina, North Dakota, South Carolina, South Dakota and the southern portion of Texas in 2023. Under O'Donnell's guidance, defensive linemen Terrence Lane II and Kyle Philbin both earned All-Ivy honorable mention honors.

In 2022, O'Connell coached cornerbacks Cooper DeVeau and Isaiah Reed, who both earned All-Ivy honorable mention honors after finishing in the top 10 in passes defensed in the conference. DeVeau tied for the second-most passes defensed with 11, while Reed tied for seventh-most with nine.

O'Donnell returned to Duke for a second stint in 2021 as a special teams/defensive analyst, where he assisted the safeties and special teams coaches.

O'Donnell spent three seasons (2018-20) with the Houston Texans. During his tenure, the Texans won back-to-back division titles and earned their fourth appearance in the AFC Divisional Round in franchise history. O'Donnell's first NFL coaching role came as a defensive quality control coach in 2018 and he served as a defensive assistant in 2019. He was named coordinator of football research/defensive assistant in 2020.

In 2020, Texans linebacker Zach Cunningham led the league in tackles with 163, the most in his seven-year career. Houston had 14 different players record at least one full sack.

In 2019, Houston won the AFC South for the second consecutive season and won an AFC Wild Card playoff game over Buffalo. Cunningham led the team with 137 tackles while linebacker Benardrick McKinney totaled 101 tackles, combining for the most by a pair of Texans teammates since 2009.

In 2018, the Texans captured an AFC South title with an 11-5 record, which marked the second-most wins in a season in franchise history and the first season with double-digit wins since 2012. Houston had six Pro Bowl selections, including McKinney, linebacker Jadeveon Clowney and defensive end J.J. Watt.

In his first stint at Duke, O'Donnell spent two seasons (2016-17) as a graduate assistant working primarily with the defense. He worked with a pair of first-team All-ACC selections, one second-team All-ACC pick and five third-team All-ACC selections on the defensive side of the ball.

In 2017, the Blue Devils ranked third in scoring defense (20.2) and fourth in total defense (332.6) across the conference. O'Donnell worked with a defense that had four players earn All-ACC honors, including two first-team selections in linebacker Joe Giles-Harris and cornerback Mark Gilbert.

In 2016, O'Donnell worked with Giles-Harris who earned Freshman All-American honors after producing 107 tackles, 4.0 sacks and one interception. His 107 tackles ranked 10th in the ACC, and he was the only freshman in the conference to break the centennial mark that season.

O'Donnell spent two seasons (2014-15) as a defensive graduate assistant at Southern Mississippi. In 2015, he helped the Golden Eagles return to a bowl game for the first time in four years, following their conference championship appearance.

O'Donnell began his coaching career as a student assistant at Iowa, where he spent two years (2012-13) working with the strength and conditioning staff. In 2013, the Hawkeyes finished with an 8-5 overall record and a trip to the Outback Bowl.

O'Donnell played linebacker at Brown University from 2008-11 and served on the team's leadership committee. He helped the Bears claim the 2008 Ivy League championship title as a freshman and earned All-Ivy honorable mention as a senior after recording 69 total tackles, the second-most on the team.

A Tipton, Iowa native, O'Donnell graduated from Brown with a bachelor's degree in economics and earned a master's degree in sports management from Southern Mississippi. He and his wife, Katie, have two sons, Bennett and Baylor.