Early years and SC Paderborn Breitenreiter started his coaching career in 2009 and worked as scout for
Kaiserslautern. On 3 January 2011, he was appointed as head coach of
TSV Havelse, club playing in
Regionalliga Nord. In 2012, he won
Lower Saxony Cup with TSV Havelse. On 15 May 2013, it was announced that Breitenreiter would take over
SC Paderborn starting in the 2013–14 season. On 11 May 2014, his club gained promotion to
Bundesliga for the first time ever in club's history. On 20 September 2014, after four undefeated games (two wins, two draws) in the German top tier, Paderborn was top of the league, ahead of European powerhouses
Bayern Munich,
Borussia Dortmund and
Bayer Leverkusen.
Schalke 04 Breitenreiter became the 14th head coach for
Schalke 04 in the last decade on 12 June 2015, signing a two-year deal with €500,000 being paid to Paderborn for his services. His debut on 8 August was a 5–0 win away to
MSV Duisburg in the first round of the
DFB-Pokal, followed a week later by a 3–0 win at
SV Werder Bremen in his first league game. His first campaign as a manager in European football ended in the last 32 of the
UEFA Europa League with a 3–0 loss to
Shakhtar Donetsk. He left the club after a single season, having come fifth and qualified for the Europa League again, but falling short of club aims of reaching the
UEFA Champions League.
Hannover 96 Breitenreiter was appointed as the new head coach for
Hannover 96 on 20 March 2017, replacing
Daniel Stendel during a time of internal changes at the fourth-placed club. On 1 April, he debuted in a 2–0 home win over
1. FC Union Berlin, ending a nine-game unbeaten run for the league leaders. He finished his nine-game run to the end of the season unbeaten, winning promotion as runners-up to
VfB Stuttgart. He was sacked on 27 January 2019 after eight consecutive losses put the team second from bottom; his last result was a 5–1 loss at Dortmund, and he was replaced by
Thomas Doll.
FC Zürich Breitenreiter took the first foreign job of his lifetime in the summer of 2021, taking over an
FC Zürich side that had avoided relegation from the
Swiss Super League on the penultimate matchday of the previous season. His team won the 2021–22 season by 14 points over
FC Basel, playing a quick counter-attacking game; only two teams averaged less possession in the entire league.
TSG Hoffenheim In May 2022, Breitenreiter signed for
TSG Hoffenheim, succeeding
Sebastian Hoeneß on a two-year deal. He was sacked the following 6 February 2023, with the club three points above the relegation zone.
Huddersfield Town On 15 February 2024, Breitenreiter was appointed head coach of English
Championship club
Huddersfield Town on a two-and-a-half-year contract. The team were in 20th, five points above the relegation zone. Nine days later, his team came from behind to win 2–1 at
Watford on his debut. On 10 May 2024, Breitenreiter left Huddersfield Town by mutual consent following the club's relegation to
EFL League One; he had won two of his 13 games. Before his final game, he told
BBC Radio Leeds that he would not have joined the club if he had been aware of "things and problems", alleging that they had spent pre-season playing golf and going to the pub.
Return to Hannover 96 On 29 December 2024, Breitenreiter returned to Hannover 96, succeeding
Stefan Leitl. He received a contract until the end of the season. On 23 April 2025, four matchdays before the end of the season, Breitenreiter and Hannover agreed to part ways early. ==Coaching record==