He rejoined Bayern in 2016 for an undisclosed fee and was sold back to Dortmund three years later, having won the Bundesliga in all his seasons in Munich.

[4] During his first full season, he quickly established himself as first-choice, as he often partnered newly signed Neven Subotić, but also missed a great part of its final months due to injury.

Hummels scored a goal in Dortmund's 5–2 win against Bayern in the 2012 DFB-Pokal Final as the team completed the league and cup double.

[12] In that season he would score his first goal in the UEFA Champions League, a penalty against Olympique Marseille in a group stage match to make it 2–0.

Hummels scored his second Champions League goal in the first leg of the round of 16 in the 2012–13 edition of the competition, equalizing late by header against Shakhtar Donetsk.

On 25 May 2013, Hummels was in the Borussia Dortmund line-up that was defeated 2–1 by Bayern Munich last-minute at Wembley Stadium, London, in the 2013 UEFA Champions League Final.

[20] On 20 August, Hummels scored his first goal for the club in a 5–0 victory over Carl Zeiss Jena during the first round of the DFB-Pokal.

[24][25] On 9 April 2017, Hummels missed the Champions League quarter-final first leg against Real Madrid after sustaining an ankle injury in training.

Javi Martínez was shown a red card in the first leg and there was no more backup player in centre-back position; the match ended 4–2 defeat for his side as they got knocked out from the competition.

[31] On 5 August 2017, Hummels started the season in fashion by defeating Borussia Dortmund to win the DFL-Supercup in the penalty-shootout as the match ended 2–2 after extra time.

[35] Hummels sustained an adductor injury at Bayern's training camp in Doha during the winter break which forced him to miss the league match against Bayer 04 Leverkusen.

[41] Hummels had a difficult spell midway through the season as he lost his starting place for several matches to Niklas Süle.

On 10 April 2024, Hummels played his 500th match for Borussia Dortmund in all competitions against Atlético Madrid during the Champions League quarter-finals.

[48] A week later he assisted Julian Brandt's goal in the second leg match against Atlético Madrid to tie the game on aggregate.

A month later, on 7 May, he scored the only goal and his fifth Champions League goal of his career from a header in a 1–0 away victory over Paris Saint-Germain in the Champions League semi-final second leg, becoming the oldest German player, aged 35 years and 143 days, to score in the knockout stages of the competition, and securing his club's qualification to the final for the third time in their history.

[52] He won the man of the match award three times that season, after a 3–1 victory over Milan in the group stage as well as twice in the semis against PSG (2–0 on aggregate) becoming the player with the most MOTM-awards in the 2023–24 UEFA Champions League campaign.

He was eventually named in the Team of the Season in that competition often playing alongside fellow centre-backs Nico Schlotterbeck and former Bayern-teammate Niklas Süle throughout the campaign.

[53] Hummels ended his season scoring four goals (including a brace against Freiburg) and reaching the fifth place in the Bundesliga with his club.

[55] On 4 September 2024, Hummels left Germany for the first time in his career and signed for Italian club Roma as a free agent on a one-year deal.

Hummels was called by the German under-21 national team for the 2009 UEFA European Under-21 Championship; after getting only minimal playing time during the initial four matches, he started as a defensive midfielder in the final, a 4–0 win against England.

On 26 May 2012, he scored his first international goal when he headed a free kick from Mesut Özil, albeit in a 5–3 friendly loss away to Switzerland at St.

[61] Hummels was in the starting line-up for Germany's opening UEFA Euro 2012 match against Portugal and helped them to a 1–0 victory.

Hummels went on to play all 450 minutes in Germany's Euro campaign, along with teammates Philipp Lahm, Sami Khedira, Bastian Schweinsteiger, Holger Badstuber, and Manuel Neuer.

Hummels scored the second goal in Germany's 4–0 win over Portugal in their first game of the 2014 FIFA World Cup on 16 June, heading a corner from Toni Kroos.

Hummels would miss the semi-final against France due to a yellow card suspension, which resulted in a 0–2 loss for Germany.

[68] He returned to the side for the final group fixture against South Korea on 27 June, but missed several chances from headers after moving up front during the second half in Germany's unsuccessful attempts to score; ultimately they were defeated 2–0 and eliminated from the tournament for the first time in the association's history.

[69] On 5 March 2019, national team coach Joachim Löw confirmed that he would plan without Hummels for the foreseeable future, along with his club teammates Jérôme Boateng and Thomas Müller.

[74] Despite his extraordinary performances in the Champions League, Nagelsmann did not call Hummels up in Germany's 26-man squad for the UEFA Euro 2024 hosted on home soil.

[75] Regarded as one of the best defenders in the world,[76] Hummels is a large, consistent, and physically strong player, known for his powerful tackling and strength in the air, as well as his positional sense, and his ability to read the game and intercept loose balls,[77][78][79] which allows him to compensate for his lack of pace.