Considered by many to be one of the greatest full-backs of all time,[3][4][5][6] Lahm was the longtime captain of Bayern Munich, having led them to numerous honours including the 2013 UEFA Champions League as part of the Treble.

Lahm is also a former captain of his national team, which he led to win the 2014 FIFA World Cup, before retiring from international football.

[11] On 13 November 2002, Lahm made his debut for the Bayern Munich first team as a 92nd-minute substitute in a 3–3 draw with RC Lens in the group stage of the Champions League.

[14] He made his Bundesliga debut on the first day of the season 2003–04 against Hansa Rostock as he came in as a substitute left back in the 76th minute for midfielder Silvio Meissner.

[14] After the Euro 2004 tournament and the resulting shorter vacation and pre-season training, he had difficulties getting off the ground and also in conforming with the tactics and system of the new coach Matthias Sammer.

[16] In January 2005, Lahm suffered a stress-fracture in his right foot and was thus sidelined for four months, making his comeback on 9 April 2005, against FC Schalke 04.

[17] During the 2005–06 season he appeared for Bayern 20 times in the Bundesliga and thrice in the Champions League, contending over field-time evenly with Bixente Lizarazu.

On 8 November 2009, Lahm was given the highest fine in the history of Bayern Munich to date (estimated to be over €25,000) after giving an unauthorised interview in the Süddeutsche Zeitung.

[25] Lahm was also chosen as vice-captain by Van Gaal, and played full-time in all of Bayern's competitive matches apart from the first-round game in the DFB-Pokal.

[36] On 26 April 2015, Bayern were confirmed as Bundesliga champions for the third consecutive season, giving Lahm the sixth league championship of his career.

[38] Leading up to the 2015–16 season, Bayern head coach Pep Guardiola stated that Lahm could return to his role at fullback with the arrivals of Arturo Vidal and Joshua Kimmich.

[41] The 2015–16 season ended with Lahm captaining Bayern to a fourth consecutive Bundesliga title; the first time a team had won four back-to-back championships in the competition's history.

[47] Lahm entered Bayern Munich's Hall of Fame on 27 May 2017; he won eight Bundesliga titles and the Champions League while playing for the club.

[49] Afterwards he played a few U20 and U21 matches for Germany before impressing Rudi Völler enough to hand the youngster his debut on 18 February 2004,[50] at 20 years of age.

His first game was a 2–1 win over Croatia, where he played the full 90 minutes and was chosen as the man of the match by German football magazine Kicker.

Lahm missed more than a year of international football between January 2005 and March 2006[52] due to injuries (stress-fracture on foot and a torn cruciate ligament), including the 2005 Confederations Cup, but after his recovery he immediately made it back to the starting line-up.

He scored the first goal in the opening game of the World Cup in Germany against Costa Rica in the sixth minute, cutting inside the area and launching a right foot shot into the top-right corner of the net.

During UEFA Euro 2008 he was in Germany's starting line-up in all games and was only substituted in the final after getting a cut needing stitches on his foot.

[54] On 29 June 2008 – in the Euro 2008 final against Spain – on 33 minutes Xavi played a piercing ball through the German defence and a lack of communication between Lahm and German goalkeeper Jens Lehmann allowed Fernando Torres to net the decisive goal in the game; Spain prevailed 1–0 to win its second European Championship title in 44 years.

Lahm did not play in the third-place (bronze) match against Uruguay due to an infection, so in his absence Bastian Schweinsteiger captained the team which won 3–2.

[57] Lahm's captaincy would later become permanent, when coach Joachim Löw announced that Ballack would not be considered to play for Germany anymore.

[58][59] Captain Lahm's solid defending helped Germany win all ten qualification matches for UEFA Euro 2012, and he also provided one assist each for Mesut Özil and Mario Gómez.

On 6 September 2013, Lahm was awarded his 100th cap for the Germany national team in a 3–0 win over Austria during qualification for the 2014 World Cup.

[63] Fritz Walter, Franz Beckenbauer, and Lothar Matthäus had skippered West Germany to the World Cup title.

[66] In August 2022, Lahm criticised the awarding of the 2022 FIFA World Cup to Qatar, citing human rights violations in the country and claimed that he would boycott the tournament.

In particular, he was renowned for his pace, technique, stamina, and precise tackling abilities, as well as his small stature, which earned him the nickname the "Magic Dwarf"; despite his size and playing role, he was described in 2010 by Matthew Scianitti of CBC Sports as having "deceptive strength and impressive shooting skills," which allowed him to assist his teams both offensively and defensively.

[72][73][74] During his time under manager Pep Guardiola, Lahm also occasionally played as a central or defensive midfielder, in a pivot role in a 3–4–3 formation, which has been likened to that of a metodista ("centre-half," in Italian football jargon), due to his ability to dictate play in midfield and act as a playmaker by starting attacks in addition to assisting his team defensively by winning back possession.