|Date of birth||24-04-1966|
|Birth place||Jerago con Orago|
|Seasons in Monza||1986-1987|
|Caps and goals||30 (0)|
Product of the Rossoneri nursery, in which he grows and forms football, he is in the squad of the first AC Milan team already in the 1985-1986 season where, however, he does not play any game. The following year (September 1986), after making his debut with Milan in the Italian Cup, he went on loan to Monza in Serie C1, where he managed to play the whole championship as a starter. He returns to Milan for the 1987-1988 season, the first with Arrigo Sacchi on the Rossoneri's bench and that will see Milan conquer its 11th league title at the end of the season. Costacurta made his Serie A debut on 25 October 1987 on the occasion of Verona-Milan (6th first leg, 0-1 the final result thanks to a goal by Pietro Paolo Virdis), but at the end of the season, closed by Filippo Galli , only manages to collect 7 league appearances and one in the Italian Cup. The 1988-1989 season opens with the victory of the Italian Super Cup against Sampdoria (3-1) for Costacurta, which becomes increasingly fundamental in the defense deployed by Sacchi. At the end of the season there will be 26 appearances in the league, and for the stopper there is also the 1st Champions Cup, won against Steaua Bucharest 4-0 in the final played at the Camp Nou in Barcelona, where Billy himself plays 74 minutes before leave room for Filippo Galli. Sacchi's triumphs of Milan did not stop and in 1989-1990, Costacurta won his 2nd consecutive Champions League, playing the final of Vienna won by AC Milan against Benfica 1-0 (goal by Rijkaard), the Intercontinental Cup ( he plays the Tokyo final against Medellín's Atlético Nacional decided by a goal by Alberigo Evani) and the European Super Cup, in the winning double final with Cruijff's Barcelona (1-1, 1-0). It is the year that sees his first goal in Serie A, scored in the return derby with Inter, it will be the goal of the momentary 1-2 of the Rossoneri, but in the end the score will see the cousins triumph for 1-3. The victories, although minor, still continue in the 1990-1991 season, which will see Costacurta always a fixed holder (25 league appearances) and winner of the 2nd Intercontinental Cup and another European Super Cup. In the meantime Azeglio Vicini called him into the national team for the first time on 22 December 1990 and Sacchi, who took over from Vicini, made him make his debut on 13 November 1991 against Norway (1-1), but Italy would not be able to qualify for the 1992 European Championships. played in Sweden. The Orago defender will also be the absolute protagonist of the Capello management, winning from 1991 to 1996, 4 badges (3 in a row from 1991-1992 to 1993-1994 and 1995-1996), 1 Champions League (1993-1994, but in the final against Barcelona will be absent due to suspension), 1 European Super Cup (1994) and 3 Italian Super Cups (1992, 1993 and 1994). He is also a permanent owner of the Italian national team coached by Arrigo Sacchi, with whom he graduated vice-world champion in 1994 on the occasion of the American World Cup. The negative seasons 1996-1997 and 1997-1998, managed by Tabárez and Sacchi before and after Fabio Capello's return, will see Costacurta always owner, as well as the 1998 World Cup played in France. The national team coached by Cesare Maldini will see his dreams fade away to the quarterfinals against France, the host and immediately after the competition Dino Zoff will land on the blue bench, setting aside Costacurta from his calls to give space to new elements and give a generational change. The advent of Alberto Zaccheroni (1999) sees Costacurta, vice-captain and central pivot of the new 3-man defense imposed by the coach from Romagna, who he will form with Paolo Maldini and the young Luigi Sala. At the end of the season Billy will still be the champion of Italy and protagonist of the 16th AC Milan title. At 33, it is the beginning of a second youth for the defender, who thus puts his 6th personal championship on the notice board and rejects the criticisms of those who gave up the players of the "old guard" like him, Paolo Maldini, Sebastiano Rossi and Demetrio Albertini. Subsequent vintages, from 1999 to 2002, will not be lavish for Alberto Zaccheroni's team (who will in any case keep Costacurta fixed holder in the center of the defense) and the coach will be exonerated in the middle of the 2000-2001 seasons to give way to Cesare Maldini. The 2001-2002 sees the Turkish Fatih Terim on the Milan bench, but after only 8 days (and results too fluctuating) Carlo Ancelotti will take the place of the former Galatasaray manager, managing to qualify Milan for the Champions League preliminaries with the 4th final place in the championship. At the end of the aforementioned season, Costacurta has an expiring contract, with him Sebastiano Rossi and José Antonio Chamot, who will join up elsewhere, while Costacurta, a little disappointed by the lack of renewal by the company, decides to leave for the United States , to attend a master's degree in economics (which he has always been passionate about) and perhaps to play the last year of his career in Major League Soccer football, where he would be welcomed like a star and covered in dollars. But in the meantime, Milan, engaged in the Champions League preliminaries against the Czechs of Slovan Liberec, must face a sudden lack of elements in the defensive sector due to injuries and it is the same CEO of the company Adriano Galliani to call (unbeknownst of the team) Costacurta from America to bring him back to Milan and renew his contract, exactly on the eve of the return match with the Czechs. Milan will struggle to overcome Slovan Liberec himself (1-0 in Milan, Filippo Inzaghi's goal and 1-2 away defeat) and will compete in a great competition that will take him to the Manchester final of 28 May 2003 against Juventus, who the rossoneri will win 3-2 on penalties. Costacurta will play that match until the 65th minute of the second half, when he leaves room for the Brazilian Roque Júnior. For "Billy" it is the fourth European Cup, to which is added the Italian Cup won in the double end-of-season match against Roma (1-4, 2-2). At 37, the veteran never ceases to amaze and is still the protagonist of the Rossoneri's victories. In fact, the following season (2003-2004) sees Costacurta win his 7th championship (better than him only Giuseppe Furino and Giovanni Ferrari with 8 championships), yet another European Super Cup (1-0 on Porto in the final, goal by Ševčenko ). For the defender, however, there are disappointments in his career, such as the defeats in the Champions League final suffered by Milan with Olympique Marseille (1992-1993), Ajax (1994-1995) and the daring one against Liverpool in Istanbul (2004-2005) or the two Intercontinental Cup finals lost consecutively against the Brazilians of San Paolo (2-3, 1993) and the Argentines of Vélez Sársfield (2-0, 1994). He was a true point of reference for the Rossoneri dressing room, boasting over 650 official matches with AC Milan and having represented a guide for all new purchases. After playing the 2004-2005 seasons at a high level, winning his 5th Italian Super Cup, and 2005-2006, both under the leadership of Carlo Ancelotti and both culminating with a second place in Serie A behind Juventus, Billy Costacurta at 40 years old he started his last season at a competitive level. He is the third Milan player in terms of appearances, after Paolo Maldini and Franco Baresi, in front of Gianni Rivera. He ended his career on 19 May 2007, at the age of 41, at San Siro in the Milan-Udinese match, which ended with the 3-2 victory of the Bianconeri from Friuli, scoring the last goal of his career on penalty (the third in Serie A, more than 15 years after the second), before leaving the field receiving a well-deserved "standing ovation" by the AC Milan people. With this goal, Costacurta becomes the oldest player to have ever scored in Serie A: with his 41 years and 25 days he has indeed beaten the previous record of Silvio Piola, who in Novara-Milan of 7 February 1954 scored at the age of 40 years, 6 months and 9 days.
He made his national team debut on 13 November 1991, at the age of 25, in the Italy-Norway match (1-1) played in Genoa. With the Azzurri he participated in the 1994 World Cup, the 1996 European Championship and the 1998 World Cup, totaling 59 appearances and 2 goals.
In the 2007-2008 season Costacurta becomes a technical collaborator of Milan, working with the coach Carlo Ancelotti, and the assistant coach Mauro Tassotti. On 3 July 2008 he obtained the first pro UEFA professional license. In July 2008 he was given for certain new coach of Pisa in Serie B, but two days before his presentation to the city he declined the offer for "family reasons" . On 27 October 2008 he undertook his first experience as a coach, signing a two-year contract with Mantua (Serie B), following the exoneration of Giuseppe Brucato. His first bench coincided with the defeat of the Virgilians in Rimini, 1-0, on 28 October 2008. After four wins, four draws and six defeats on 9 February 2009, he resigned.