He left Tottenham for LA Galaxy in 2011, and in January 2012 went to Aston Villa on a two-month loan during the Major League Soccer (MLS) off-season.

[18] During a successful season at Coventry, he played a major role in a stylish attacking side boasting the likes of Gary McAllister, Mustapha Hadji and Youssef Chippo and formed a productive strike partnership with Cédric Roussel.

[24] Keane made 14 appearances for Inter in all competitions scoring three goals, his most memorable coming two minutes into the Supercoppa Italiana match against Lazio.

[28] Meanwhile, Leeds sunk deeper into debt and were forced to sell many players, with Keane joining the exodus when he was sold to Tottenham Hotspur just before the 2002–03 transfer deadline for a fee of £7 million.

[32] In the 2003–04 season, Spurs battled with relegation, but Keane's goals played a major part in helping secure Tottenham's Premier League status.

[6] The frustration culminated in Keane storming from the dugout towards the end of a game against Birmingham City in April 2005 after all the substitutes had been used, meaning he would not get a chance to appear.

[39] Keane was involved in a training ground fight with teammate Edgar Davids in December 2005, but the pair subsequently made up publicly and were seen encouraging each other on the pitch.

[54] Amid accusations that Liverpool had unsettled the player, Tottenham Hotspur filed a complaint to the Premier League regarding the club's conduct.

[84] During Tottenham's League Cup Fourth round match, Keane scored one of two goals against Everton on 27 October 2009 at White Hart Lane.

[87] On 1 February 2010, Keane signed for Celtic in a loan deal until the end of the 2009–10 season and was assigned the number 7 shirt, previously worn by Jimmy Johnstone and Henrik Larsson.

[105] After playing for the newly reformed New York Cosmos in Paul Scholes's testimonial match,[106] Keane joined LA Galaxy of MLS,[107] becoming one of the club's three allowed designated players, alongside David Beckham and Landon Donovan.

The Galaxy traded their previous third Designated Player, Juan Pablo Ángel, to city rivals Chivas USA to make room for Keane.

[108] He made his debut on 20 August 2011, in a California Clásico game against the San Jose Earthquakes, and scored his first goal for his new team in the 21st minute, in a 2–0 win at The Home Depot Center.

[120] He finished with 16 regular season goals, fourth in the league's top scorers, and was one of three strikers named in the MLS Best XI, alongside Thierry Henry and Chris Wondolowski.

[126] On opening day, he had a part in each goal as Galaxy beat Chicago Fire 4–0 at home, assisting a hat-trick for Mike Magee before himself finding the net in added time.

[131] For the second consecutive season, he made the MLS Best XI, as recognition for his 16 goals and 11 assists, statistics which put him fourth and third on the respective top scorer lists.

[134] Keane scored his 50th MLS regular-season goal on 28 September, chipping New York Red Bulls goalkeeper Luis Robles to open a 4–0 victory.

[139] On 17 June, Keane scored a hat-trick in the fourth round of the Lamar Hunt U.S. Open Cup, as the Galaxy won 6–1 against fifth-tier amateurs PSA Elite.

[149] In total, he scored 104 goals in 165 appearances during his six seasons with the club with his last game being the MLS Cup Playoff penalty-shootout defeat to Colorado Rapids on 6 November 2016.

[159] After contesting the final three matches as player-manager, Keane decided to leave the club at the end of the season and stated he would be taking time out to consider his options.

[162] Under the guidance of Brian Kerr, the unfancied Republic of Ireland won the UEFA U16 and U18 European championships in 1998, and Keane was part of the victorious U18 side in Cyprus.

[182] After a disappointing tournament in Poland, Keane brought his international tally to 54, with an 89th-minute penalty against Kazakhstan in the Republic of Ireland's opening World Cup 2014 qualification match.

[192] Keane was selected in manager Martin O'Neill's 23-man squad for UEFA Euro 2016 in what would be his final major tournament appearance for the Republic of Ireland.

[197] Keane was also given a guard of honour from his Republic of Ireland teammates after the match had finished and he left the pitch with his two sons to rapturous applause from the home fans.

His former Leeds and Tottenham teammate Jonathan Woodgate, who had been appointed the manager of the Teesside-based club, offered him the role as part of a refurbished coaching team.

[206][207] On 26 June 2023, Keane was appointed new head coach of Israeli Premier League side Maccabi Tel Aviv, signing a two-year contract with the club and taking over his first managerial role.

[216] Keane's team reached the last 16 of the Europa Conference League and took a 4–1 win in the first leg away to eventual winners Olympiacos, but lost 7–5 on aggregate after extra time.

[219] In November 2024, Keane's wife said that the family were still receiving threats from a small number of pro-Palestine activists, which had made her doubt their safety in Ireland.

A talented, quick, and agile player,[231][232] Keane was a versatile forward, capable of playing anywhere along the front line,[233] due to his ability to score and create goals.

[232][233] A technically gifted, intelligent, and hard-working forward,[231][233] Keane was also renowned for his pace, dribbling skills, and creativity, and also stood out for his leadership throughout his career.