In July 2001, Karimi signed a two-year contract with UAE Pro League club Al-Ahli Dubai.

[9] While an Al-Ahli player, Karimi won two cup titles, and was the top goalscorer in the 2003–04 season, an impressive feat for a midfielder.

After leaving the club in 2005 aged 26, Karimi made a long-awaited move to Europe to play for Bayern Munich.

Renowned for his on-the-ball skill, dribbling runs and playmaking ability, he was often referred to as the Asian Maradona[10]‏[11] and The Magician.

[16] Karimi started his professional career with second-division side Fath Football Club in 1997 where training was conducted on the streets with a plastic ball.

Still, Karimi opted for United Arab Emirates side Al-Ahli because he wanted to stay close to home.

[18][19] Karimi signed with Al Ahli in the United Arab Emirates in 2001 for a reported salary of $1.3 million for two years.

[26] Six weeks into the league, Karimi scored his second goal assist in the Bundesliga, setting the stage for a 1–0 win against Eintracht Frankfurt and was recognized as the man of the match.

[29][30] He was also recognized as Bayern Munich's best player by scoring 2.5 points from kicker magazine in the 22nd Bundesliga match, which ended with a 1–1 draw against Hannover.

[31] Karimi made his 25th appearance for Bayern on 4 March 2006 against Hamburg, which resulted in an automatic 12-month extension to his one-year contract that expired on 30 June 2007.

[33] Karimi's average scores in the Bundesliga and the UEFA Champions League in the 2005–06 season are the best among the three Iranian players in the kicker magazine.

[38] In the 32nd week of the Bundesliga, Karimi became the foundation for Bayern's 1–1 draw against Borussia Mönchengladbach by sending a goal assist.

In this competition after Mehmet Scholl; Karimi was recognized as the second-best player of Bayern together with Hasan Salihamidžić by scoring 2.5 from kicker magazine.

He is the best ever from Iran," After Karimi's position in support of the 2022 Iranian protests following the death of Mahsa Amini,[45] FC Bayern Munich announced on 5 November 2022 that "due to concerns regarding the health condition of Ali Karimi and other Iranian players of Bayern Munich, we have long since been in touch with the German ambassador to Tehran.

Karimi was believed to have signed a contract worth around £3.2 million, with a clause allowing him to return to Europe anytime.

[51] However, Karimi's contract was not extended, reportedly because of a strained relationship with Persepolis chief executive Abbas Ansarifard.

[citation needed] Karimi joined newly promoted Steel Azin on 29 July 2009 on a one-year deal.

[54] In January 2010, it was reported that Al-Ahli made an offer of US$500,000 to sign Karimi on a loan deal until the end of the 2009–10 season, which Steel Azin rejected.

[55] Karimi was sacked by the club in August 2010 for failing to observe the fast requirement during Ramadan, but was reinstated a few days later after paying a fine.

[63] Karimi was given the prestigious Asian Player of the Year award in 2004, joining his fellow Iranians, Mahdavikia in 2003, Ali Daei in 1999, and Khodadad Azizi in 1996.

His performance in the Iran–Germany friendly game for Bam victims held in Azadi Stadium in Tehran in October 2004 was said to be the reason behind Bayern's interest in the player.

Iran's then manager Branko Ivankovic said he may drop Karimi in the upcoming game due to disciplinary reasons.

In May 2008, Karimi was banned from playing in the national team after he made criticisms towards the IRIFF in the Ardebil training ground,[68] but was reinstated in the national squad after intervention from Iranian President Mahmoud Ahmadinejad and Hassan Khomeini, the grandson of revolutionary leader Ayatollah Ruhollah Khomeini.

[70] In April 2009, Karimi announced that he was ready again to serve his country if he was to be picked by Team Melli coach, Afshin Ghotbi.

[17] In 2004, kicker magazine called Karimi the "Maradona of Asia" in a report: "He shoots well with both feet, changes direction very quickly and is a player who makes the opposing team dizzy.

[12] In a report in 2017, AFC called Karimi the "Maradona of Asia" and introduced him as "one of the Icons of Asian football history".

In the continuation of this report, "magical dribbling skills" and "a knack for the unpredictable" are mentioned as characteristics of Karimi's game.

[78] In addition to his criticism of the government, he used his platform of 14+ million followers to advise Iranians on how to bypass Internet censorship in their country.

[79] Based in Dubai, he was charged in absentia by Iran with "encouraging riots",[80] and his house in Lavasan was seized by the Iranian state.

[81] On 18 January 2023, Karimi publicly tweeted his support for exiled crown prince Reza Pahlavi to assume a role as representative of the Iranian people pending a national referendum.