He began his career at Milan, making his Serie A debut at the age of 17. In 2009, he joined Padova on loan, whom he helped avoid relegation from Serie B in his only season there. He then signed for Palermo in 2010, and one year later joined Torino, where he played for four seasons. He moved to Manchester United in July 2015, winning the FA Cup in his first season with the club.
Darmian made his senior debut for the Italy national team in May 2014, and represented his nation at the 2014 FIFA World Cup and UEFA Euro 2016.
Darmian grew up playing football in the main square in Rescaldina and was trained by his father, Giovanni, who was one of the coaches of Oratorio team, U.S. CARCOR, where players such as Marco Simone and Luigi Pogliana also played. His first real break came when he was spotted by Beniamino Abate, a former goalkeeper tasked with scouting Lombardy for young talent by Milan.
In 2000, he joined Milan's youth system. He made his first-team debut for the Rossoneri on 28 November 2006, aged only 16, in the Coppa Italia against Brescia, replacing Kakha Kaladze at half-time.
He made his Serie A debut at the age of 17, in Milan's 3–2 defeat against Udinese on 19 May 2007, when he entered in the 67th minute to replace Giuseppe Favalli. During the 2007–08 season he became the leader and captain of the A.C. Milan Primavera, collecting another appearance for the first-team in the Coppa Italia. The following season, the 19-year-old defender collected an additional three league appearances. He ended his experience at Milan with four appearances in the top flight.
On 17 July 2009, Darmian moved to Serie B club Padova on loan until the end of the 2009–10 season. He made his official debut for the club on 28 November 2009, in a home loss against Vicenza. He went on to make 20 appearances and score one goal, as Padova finished the season in 19th place and subsequently won the relegation play-off against Triestina.
On 11 July 2010, it was announced that Matteo Darmian would join Palermo's pre-season training camp in Austria, after Milan and the Sicilian Serie A club agreed in principle about a transfer move involving him. The move, unveiled as a co-ownership bid, was officially announced by Palermo the next day. The fee was €800,000. Darmian made his debut for the Rosanero on 16 September 2010, in a Europa League game against Sparta Prague, which also earned him his debut in European competition. His Palermo league debut was during the fourth game of the season, coming on for Javier Pastore in a 3–1 win against Juventus. On 6 February 2011, he played his first game as a starter in the league in a 4–2 victory for Palermo away at Lecce, but was substituted in the 33rd minute due to injury. He finished the season with 16 appearances among Serie A, Europa League and Coppa Italia.
After Milan and Palermo renewed the co-ownership on 23 June 2011, he was officially loaned to Serie B side Torino on 12 July 2011. He made his debut for the Granata on 13 August 2011, in the second round of Coppa Italia against Lumezzane; and scored his first goal on 30 October 2011, against Empoli, allowing his team to win 2–1. On 13 November 2013, he was injured against Bari and sidelined for five games. At the end of the season, he was promoted to Serie A, having played 33 games in the league and one in the Coppa Italia.
On 20 June 2012, Palermo redeemed his 50% share from Milan for €500,000 and on 5 July 2012, his return to Torino was formulised under a co-ownership agreement for €825,000. With Torino he played 30 games in Serie A and two in the Coppa Italia. On 20 June 2013, Torino redeemed the remainder of his contract from Palermo for €1.5 million.
In the 2013–14 season, he played 37 games in Serie A for Torino, who finished 7th and qualified for the Europa League after Parma failed to obtain a UEFA license. He featured in the Serie A Team of the Year, along with teammate, Ciro Immobile. On 18 May 2014, he made his 100th appearance for Torino during the 2–2 draw away to Fiorentina.
In his first appearance of the 2014–15 season, on 7 August 2014, he scored his first goal in European competition, in a 4–0 victory against Sweden's IF Brommapojkarna, in the second leg of the 2014–15 Europa League third qualifying round. On 29 October 2014, he scored his first goal in Serie A to secure a 1–0 win over Parma, before returning to the score-sheet on 11 December 2014 in the Europa League group stage, won 5–1 away at Copenhagen. On 26 February 2015, he scored the match-winner against Athletic Bilbao, qualifying Torino for the round of 16 after a historic 3–2 victory in Spain. He concluded the season with 47 appearances and five goals between Serie A, Europe and the Coppa Italia.
In total, he played 151 matches and scored six goals for Torino.
On 11 July 2015, Darmian signed for English club Manchester United for an undisclosed fee, believed to be £12.7 million. He signed a four-year contract with an option to extend it for a further year. He made his debut for the club against Club América during preseason on 17 July 2015, playing the first 45 minutes, with United winning 1–0. He made his Premier League debut on 8 August 2015 as the season opened with a 1–0 victory against Tottenham Hotspur at Old Trafford, with manager Louis van Gaal selecting his performance as the best of the match.
On 10 September 2015, Darmian earned his first official accolade at the club, after he was voted Manchester United's August 2015 player of the month. "It's important to know this is from the fans," Matteo told United's official website. "I want to thank them. I am happy. I also want to thank my team-mates and everyone at the club for making me feel welcome."
In his twenty-seventh league appearance of the 2015–16 season, on 20 April 2016, Matteo scored his first Manchester United and Premier League goal, a powerful volley from the edge of the penalty area, in a 2–0 victory against Crystal Palace. He was presented with the club's Man of the Match award for his performance in this fixture and hailed his 55th-minute strike as the best goal of his career, thus far. His cross, in the fourth minute of play, had also previously forced an own goal from Damien Delaney.
After playing for Italy at under-17 and under-18 levels, he was called up to the under-19 squad, led by Francesco Rocca, in July 2008. At the UEFA European U-19 Championship he played in the starting lineup, always in the role of a right full-back. In 2009, he took part in the Mediterranean Games, playing seven games for the under-20 side. On 25 March 2009, he made his debut for the Italy under-21 side in a 2–2 friendly match draw against Austria, which was played in Vienna. From 10 to 12 March 2014, he was called up to the senior national team by coach Cesare Prandelli as part of an internship to evaluate young players ahead of the 2014 FIFA World Cup, and was also part of the next meeting between 14 and 15 April 2014.
Given his excellent season with Torino, on 13 May 2014, he was included in the list of 30 provisional players for the 2014 World Cup. He made his debut for the Azzurri on 31 May 2014, at the age of 24, playing as a right-back in a goalless friendly match with Ireland which was held in London. The following day, he was included in the list of 23 players selected for the 2014 World Cup. On 14 June 2014, he made his debut at the World Cup, starting Italy's opening game against England, which Italy won 2–1. He also played the next two games against Costa Rica and Uruguay, both of which were 1–0 defeats for Italy who failed to qualify for the next round.
In early 2015, he was awarded with the Pallone Azzurro as the best player of the national team for 2014. On 10 October of that year, he scored his first international goal, which was the final one of a 3–1 away win over Azerbaijan which sealed Italy's qualification to UEFA Euro 2016. On 31 May 2016, he was named in Antonio Conte's 23-man Italy squad for Euro 2016. In the round of 16 of the tournament, at Stade de France in Paris on 27 June 2016, he came off the bench and set-up Graziano Pellè's 91st minute volley to give the Azzurri a 2–0 win over defending champions Spain. On 2 July 2016, he missed Italy's final penalty in a 6–5 shoot-out defeat to reigning World Cup champions Germany in the quarter-finals of the competition.
Although he started his career as a centre-back, and has occasionally continued to be used in this role, in recent years Darmian has predominantly played as a full-back or wing-back; due to his ability with both feet, he is capable of playing on either flank, although he prefers to be deployed on the right side of the pitch. An intelligent, dynamic, hard-working, and versatile player, he is known for his good quality of offensive and defensive play, as well as his tactical awareness, pace, and stamina, attributes which allow him to cover the wing effectively and provide width to his team when attacking; his professionalism, as well as his promising and consistent performances in his youth, led him to be compared to several esteemed Italian former full-backs, such as Antonio Cabrini and Paolo Maldini. During the 2012–13 season, Darmian made the most tackles per game (5.3) across Europe's top five leagues.As of match played 20 September 2017
As of match played 5 September 2017
As of match played 5 September 2017. Scores and results list Italy's goal tally first.
FA Cup: 2015–16
EFL Cup: 2016–17
UEFA Europa League: 2016–17
Serie A Team of the Year: 2013–14, 2014–15
Pallone Azzurro: 2014