Early years
Simeone ended his playing career for Racing Club, playing his last match on 17 February 2006, and then became manager for the same team. After a rough start, the team made an impressive finish in the 2006 Clausura. When a new club president was elected, Simeone left Racing in May 2006 and was replaced by Reinaldo Merlo.
On 18 May, Simeone became head coach of Estudiantes and soon led them to their first league title in 23 years after defeating Boca Juniors 2–1 in a final match played on 13 December 2006. In an October 2006 poll in the sports daily Olé, Simeone was voted as the best manager in the Argentine league. He was also praised as a "born manager" by former Argentine international Roberto Perfumo. Simeone left Estudiantes after the end of the 2007 Apertura, where Estudiantes was not a contender after a poor start, but had a strong finish of nine games without defeat. On 15 December 2007, Simeone was unveiled as the new River Plate coach, succeeding Daniel Passarella. The contract was reported to be for one year, starting on 3 January 2008. After an early elimination in the Copa Libertadores, losing to San Lorenzo in the second round, Simeone and River Plate went on to win the 2008 Clausura championship after beating Olimpo 2–1 in the Monumental. On 7 November 2008, Simeone announced his resignation as coach of River Plate after their elimination in the quarter-finals of the 2008 Copa Sudamericana by Mexican side Chivas and a poor run of form of 11 domestic matches without a win, which left them bottom of the Primera División Argentina with only six matches remaining. On 15 April 2009, Simeone joined San Lorenzo to replace Miguel Ángel Russo following the club's exit in the first round of the 2009 Copa Libertadores. On 3 April 2010, Simeone resigned from San Lorenzo due to poor results and mounting criticism.
Catania and Racing Club
On 19 January 2011, Simeone flew to Sicily to join Serie A side Catania, replacing Marco Giampaolo, who left the club just hours earlier. On 1 June 2011, Simeone left his post after helping Catania stave off relegation. On 21 June 2011, Simeone was named as the new coach of Racing Club for a second spell in charge, replacing Miguel Ángel Russo, who had resigned the week prior.
2011–13: Europa League and Copa del Rey triumphs
On 23 December 2011, Simeone was unveiled as the new Atlético Madrid coach, succeeding Gregorio Manzano, who had been dismissed the day before following defeat to third-tier Albacete in the Copa del Rey. His first game as Atlético manager was a 0–0 away draw against Manuel Pellegrini's Malaga. His first season ended with the team winning the UEFA Europa League by beating Athletic Bilbao 3–0 in the final in Bucharest.
On 31 August 2012, his Atlético side won the UEFA Super Cup after defeating Chelsea 4–1 at the Stade Louis II in Monaco. In the domestic league, the team made an impressive start to the season, finishing the first half in second place, behind only Barcelona and above city rivals Real Madrid. Eventually, Simeone led the team to a third-place finish in the league, which at the time was the best finish in 17 years for Atlético. On 17 May 2013, he won the Copa del Rey after Atlético defeated rivals Real Madrid 2–1 at the Santiago Bernabéu.
2013–17: La Liga win and Champions League finals
Atlético began the 2013–14 season with a similar squad to their prior season, despite selling star player Radamel Falcao to Monaco for a reported €60 million fee. They also acquired David Villa from Barcelona on a free transfer. While the season began with a defeat to Barça in the 2013 Supercopa de España, the team recorded eight-straight victories in La Liga, the best league start in club history. This included a 1–0 away win at the Santiago Bernabéu against Real Madrid, making Simeone the first Atlético manager since Claudio Ranieri in 1999 to record a league victory there. Atlético finished the first half of the season in first place in La Liga, level on points with Barcelona at 47. In the last round of the season, on 17 May, Atlético needed at least a draw in the Camp Nou against Barcelona to be crowned champions for the first time since 1996, while a loss would give the title to Barcelona. A Diego Godín header from a corner kick in the 48th minute gave Atlético an equaliser and the draw they needed to win their tenth league title and first since 1996, when Simeone himself was an Atlético player.
Simeone became the second Argentine manager after Helenio Herrera to hand Atlético a Spanish championship, and the second manager after Luis Aragonés to win it both as a player and as a coach of the team. Under Simeone, Atlético collected 90 points in La Liga, surpassing its 1996 record of 87, making the 2013–14 season the most successful in club history.
Also in 2013–14, Atlético finished top of their Champions League group and qualified for the quarter-finals with a 5–1 aggregate win over Milan in the round of 16. This was the first time they had reached the Champions League quarter-finals since 1996–97, when Simeone played for the team. In the quarter-finals, Atlético defeated Barcelona 2–1 on aggregate from Simeone's tactic of cutting the swift-passing midfield of Barcelona in two, thus denying them space and isolating Xavi and Andrés Iniesta from forwards Lionel Messi and Neymar. In the semi-finals, Atlético defeated José Mourinho's Chelsea 3–1 at Stamford Bridge following a goalless draw at home to reach the Champions League final for only the second time in club history, the first being in 1974. Atlético was the only undefeated team in the Champions League prior to the final, recording nine wins and three draws, and had the best defence in the competition, conceding only 6 goals in 12 matches.
In the final on 24 May 2014, Atlético faced city rivals Real Madrid at the Estádio da Luz in Lisbon. Despite leading from Diego Godín's header, Atlético conceded a late equaliser in the 93rd minute of the match. The goal hampered Atlético's morale, and the team ended up losing 4–1 after extra time, with Simeone losing the opportunity to be the third Argentine coach to win the Champions League, after Luis Carniglia and Helenio Herrera. After the final goal, Real Madrid's Raphaël Varane kicked the ball towards Simeone, causing Simeone to run onto the pitch in anger. He was sent to the stands, and Varane was booked for the incident. Reflecting, Simeone said, "I also made a mistake with my reaction. He's a young guy with a bright future." Simeone also admitted a mistake in selecting striker Diego Costa to start the match, as he had been recently injured and was forced off after eight minutes.
In the summer of 2014, Chelsea acquired Diego Costa, Filipe Luís and Thibaut Courtois from Atlético, and also David Villa moved to the MLS. In response, Atlético acquired striker Mario Mandžukić from Bayern Munich, goalkeeper Jan Oblak from Benfica and forwards Antoine Griezmann from Real Sociedad and Ángel Correa from San Lorenzo, and recovered young midfielder Saúl who was on loan at Rayo Vallecano. The season started with Atlético defeating city rivals Real Madrid for the Spanish Super Cup in August and repeating the previous year's victory in the Bernabéu for the league in September. In January, the team acquired Fernando Torres on loan from Milan. However, Atlético finished the league in third place and was eliminated in the UEFA Champions League quarter-finals by Real Madrid 1–0, on aggregate.
Before the start of the 2015–16 season, Filipe Luís returned from Chelsea with the team also acquiring Montenegrin defender Stefan Savić and Belgian midfielder Yannick Carrasco. Mario Mandžukić left for Juventus. In 2015–16, Atlético was the team with the best defensive record in Europe's "big five" leagues, only allowing 18 goals scored against them in 38 La Liga games. Atlético was also the team with the most clean sheets in their games. The team was contending the league title until the last fixture against Barcelona and Real Madrid, settling for third with 88 points.
In the UEFA Champions League, Simeone led Atlético to their second Champions League final in three seasons, becoming the first Argentine manager since Héctor Cúper to reach two Champions League finals. Atlético had defeated PSV on penalties during the round of 16, beat defending champions Barcelona 3–2 on aggregate and favourites Bayern Munich 2–2, going through on away goals, setting up a repeat of the 2014 final again facing Real Madrid. The match ended 1–1 after extra time leading to a penalty shootout. Juanfran was the only player to miss his kick, enabling Cristiano Ronaldo to score Real's last spot kick, condemning Atlético to a second Champions League final defeat in three seasons.
In the summer of 2016, Atlético purchased forward Kevin Gameiro from Sevilla, midfielder Nicolás Gaitán from Benfica, and defender Šime Vrsaljko from Sassuolo. They also acquired the rights to Fernando Torres (previously on loan from Milan). The team again finished third in the league and lost in the UEFA Champions League semi-finals, again to Real Madrid.
2017–21: Second Europa League and La Liga victories
On 5 September 2017, Simeone extended his contract with Atlético for two more years, until June 2020. In the 2017–18 season, Atlético would finish in second place in La Liga, behind Barcelona but ahead of city rivals Real Madrid.
In the 2017–18 UEFA Champions League group stage, Atlético did not advance and dropped to the 2017–18 UEFA Europa League. In January 2018, Diego Costa returned to Atlético from Chelsea. On 16 May 2018, the team won the 2018 UEFA Europa League Final against Marseille. Simeone was sent to the stands in the first leg of the semi-finals against Arsenal and was suspended. He was forced to watch the second leg and final from the stands.
In the 2018–19 season, Atlético bought Thomas Lemar from Monaco and Rodri from Villarreal, and in January 2019 acquired Álvaro Morata on loan from Chelsea, while longtime team captain Gabi signed for Qatari club Al-Sadd before the start of the season. They started the season by winning the 2018 UEFA Super Cup against arch-rivals, Real Madrid, winning 4-2 after extra time. The team again finished second in the league behind Barcelona and ahead of city rivals Real Madrid. In the Champions League, they advanced to the first knockout round, where they were eliminated by Juventus, winning the first leg 2–0 at the Wanda Metropolitano but losing the return leg 3–0 in Turin.
Simeone guided his side into the last 16 of UEFA Champions League for the sixth time since he came to reign in 2011, while before his arrival Atlético had only done so seven times in 60 years. On 11 March 2020, Atlético Madrid eliminated the reigning European champions Liverpool with a 3–2 triumph after extra-time at Anfield, winning 4–2 on aggregate, after Saúl secured a 1–0 first-leg win in the reverse via a 5th-minute strike.
On 27 June 2020, Simeone won his 195th game in the top-flight of Spanish football as Atleti beat Alavés 2–1 on Saturday. With the triumph, the Argentine has overtaken the club legend, Luis Aragonés (194), as the manager with the most La Liga wins in the club's history.
On 7 July 2020, Simeone overtook John Toshack as the third coach with the most games managed at a single club in the history of the top-flight of Spanish football during Atleti's match against Celta Vigo, his 323rd game in La Liga. Only Miguel Muñoz (Real Madrid, 424) and, the club legend, Luis Aragonés (407) remain ahead of him.
For the 2020–21 season, Atlético parted ways with longtime-serving forward Diego Costa and acquired Luis Suárez after his departure from Barcelona. The team brought back Yannick Carrasco from Dalian Professional and also acquired Geoffrey Kondogbia from Valencia, Lucas Torreira on loan from Arsenal and Moussa Dembelé on loan from Lyon, while Thomas Partey left for Arsenal and Álvaro Morata was loaned to Juventus. On 17 October 2020, Simeone reached his 200th win in the league in a 2–0 away win against Celta Vigo. On 30 December 2020, he reached his 500th match in charge of Atlético Madrid in a 1–0 win over Getafe.
On 10 March 2021, Simeone overtook Luis Aragonés for the most wins ever as manager of the club in a 2–1 home win against Athletic Bilbao, his 309th win overall.
After a 4–0 away defeat to Bayern Munich and many injuries to key players in November 2020, Simeone modified the formation of his squad by introducing a three-man defence for the first time in his tenure coaching Atlético. In this formation, Carrasco played as a wing-back, with left centre-back Mario Hermoso being instructed to also cover the left-back position when Carrasco moved forward, which made the formation tactically flexible between a three-man and four-man defence. After the formational change, Atlético were solidified defensively and began a streak of victories, including a 1–0 home victory against Barcelona. This streak propelled the team to a ten-point lead over Real Madrid and Barcelona in the 2020–21 La Liga title race by February. However, a series of bad results from February to April meant that Atlético were eliminated from the Champions League by Chelsea and Real Madrid closed the league gap to two points before the final matchday, meaning Atlético needed a victory in the last La Liga round to win the championship. Thanks to a Suárez goal in the 67th minute, Atlético Madrid managed eventually to win their second La Liga title under Simeone, after a 2–1 away win over Real Valladolid on the final match day.
On 8 July 2021, Atleti announced their extension to Simeone's contract until 2024, and in the same announcement it was also made known that the members of his coaching staff had also renewed their contracts.
2022–present: Contract extension and new records
On 9 November 2023, Simeone extended his contract with Atlético Madrid until 30 June 2027. Later that month, on 28 November, he managed his 100th Champions League match in a 3–1 away victory over Feyenoord, becoming the third manager to achieve this feat with one club following Alex Ferguson and Arsène Wenger. On 23 November 2024, he managed his 700th match with the club in all competitions in a 2–1 victory over Alavés. On 2 May 2026, Simeone reached his 1000th career match as a manager in a 2–0 away win over Valencia.