Georgia In May 2010, Macdonald joined
Mark Richt's coaching staff as a graduate assistant with the
Georgia Bulldogs football program. He also served as a safeties and defensive quality control coach at Georgia from 2011 to 2013. In 2013, while coaching at Georgia, Macdonald earned a
master's degree in
sport management from the Mary Frances Early College of Education at the University of Georgia.
Baltimore Ravens Macdonald served on
John Harbaugh's coaching staff with the
Baltimore Ravens for seven seasons from 2014 to 2020. He was hired as an intern in 2014 and was promoted to defensive assistant in January 2015, defensive backs coach in January 2017, and linebackers coach in January 2018.
Michigan In January 2021, Macdonald joined
Jim Harbaugh's staff at Michigan, as the
defensive coordinator of the
Michigan Wolverines football program. In Macdonald's lone season
at the University of Michigan, the Wolverines posted a top 10 national defense, went undefeated at home, won the
Big Ten Conference Championship, and played in the
College Football Playoff. The team finished with a national ranking of No. 3 and a final record of 12–2.
Baltimore Ravens (second stint) On January 27, 2022, Macdonald was re-hired by the Ravens as their defensive coordinator under head coach
John Harbaugh, replacing
Don Martindale. In 2022, Macdonald led the Ravens' defense to only allowing 315 points in 17 games. Averaging just under 19 points per game, the Ravens' defense was ranked the fourth best defense in the league. In
2023, the Ravens' defensive unit improved under Macdonald as they only allowed 280 points in total on the season, the fewest in the NFL. The Ravens would advance to the AFC Championship Game, and despite losing to the eventual
Super Bowl champions, the
Kansas City Chiefs, the Ravens held the Chiefs to just 17 points, marking the team's sixth consecutive game where they held an opponent to 20 points or less.
Seattle Seahawks (2024–present) parade in 2026 On January 31, 2024, Macdonald was hired by the
Seattle Seahawks as their head coach to replace
Pete Carroll. He beat out
Ejiro Evero,
Patrick Graham,
Ben Johnson,
Mike Kafka,
Raheem Morris,
Dan Quinn,
Bobby Slowik, and
Frank Smith for the job. At the time of his hiring, Macdonald was the youngest head coach in the NFL. At his introductory press conference, Macdonald said he initially intended to retain defensive playcalling duties, but would relinquish them "when it becomes obvious that someone else is ready to go and we see it the same way." Macdonald began his inaugural season with Seattle by leading the team to three straight victories for the first time since
2020. The team followed this start by going on a three-game losing streak. By the Seahawks' Week 10
bye, the team held a record of 4–5, falling to last place in the
NFC West. The team improved to 5–5 in Week 11 when they defeated the reigning
NFC champions and division rivals, the
San Francisco 49ers on the road 20–17. In Week 18, Macdonald led the team to a 30–25 victory against the division rival
Los Angeles Rams on route to his 10th coaching win in his first season, becoming the first head coach in franchise history to reach 10 wins in his inaugural season. The Seahawks finished with a 10–7 record but missed the postseason in Macdonald's first season as head coach. In his second season after a Week 4 road victory over the
Arizona Cardinals, Macdonald became the fifth head coach in NFL history to win nine of his first 10 road games. His 10 consecutive road victories also stand as the longest streak in franchise history. After defeating the
San Francisco 49ers by a score of 13–3 in Week 18 and holding
Kyle Shanahan to the lowest offensive point and yardage total of his coaching career, the Seahawks finished the regular season at 14–3, setting a franchise record for wins in a season and winning the NFC West and finishing as #1 seed in the NFC. At the end of the regular season, Macdonald was named a finalist for the AP NFL Coach of the Year award alongside
Liam Coen,
Ben Johnson,
Kyle Shanahan, and
Mike Vrabel; Vrabel eventually won. During the 2025 season, Macdonald’s defense, who had named themselves “the Dark Side,” allowed just 292 points (17.2 per game), the fewest in the league. That figure contributed to a league-best and franchise record +191 regular-season point differential; the defense was also ranked the best in the league by
DVOA. Macdonald won the first playoff game of his career when the Seahawks defeated the 49ers in a rematch in the divisional round by a score of 41–6. In the NFC Championship, the Seahawks won 31–27 against the
Los Angeles Rams, thus qualifying for
Super Bowl LX. In Super Bowl LX, the Seahawks defeated the
New England Patriots 29–13, giving Macdonald his first Super Bowl win as a coach and the second title overall for the Seahawks franchise. He also became the first head coach in NFL history to win the Super Bowl while calling the defensive plays. At age 38, Macdonald became the third-youngest head coach to win a Super Bowl, behind
Sean McVay and
Mike Tomlin. ==Defensive philosophy==