Nicholas Hilmy Kyrgios[6] (/ˈkɪriɒs/ KIRR-ee-oss; Greek: Νικόλαος Χίλμυ Κύργιος, romanized: Nikólaos Chílmi Kírios; born 27 April 1995) is an Australian professional tennis player.

Kyrgios is only the third player, after Dominik Hrbatý and Lleyton Hewitt, to have beaten each one of the Big Three (Novak Djokovic, Roger Federer, and Rafael Nadal) the first time he played against them.

[7][8] Kyrgios is often described as a "polarising player" because of his "unique, unfiltered and unapologetic personality" which goes alongside his "on-court brilliance and audacious shot-making" in both singles and doubles.

[29] At the 2013 Nature's Way Sydney Tennis International, he defeated fellow Australian Matt Reid in straight sets in the finals to win his first challenger tour title at the age of 17.

After defeating Stéphane Robert in the first round, he went on to beat Richard Gasquet in a five-set second-round thriller; wherein, he lost the first two sets and saved nine match points.

[45] Post-Wimbledon, at the Rogers Cup tournament in Toronto, Kyrgios earned his first ATP World Tour Masters event win, with a first round victory over Santiago Giraldo in straight sets.

[47] In the US Open, Kyrgios made it to the third round, defeating Mikhail Youzhny and Andreas Seppi on his way, before losing to 16th seed Tommy Robredo.

At the Estoril Open, Kyrgios reached the final of an ATP tournament for the first time in his career, after defeating Albert Ramos Viñolas, Filip Krajinović, Robin Haase and Pablo Carreño Busta.

Kyrgios won his maiden ATP title at the Open 13 in Marseille by defeating Richard Gasquet in the quarterfinal, Berdych in the semi-final and lastly, Čilić in the final, all in straight sets.

At the 2016 Miami Open Kyrgios reached his first ATP World Tour Masters 1000 semifinal, with straight-set wins over Marcos Baghdatis, Tim Smyczek, Andrey Kuznetsov and Milos Raonic – before losing in the semis to Kei Nishikori.

Similarly, at Wimbledon (as the 15th seed), he advanced to the fourth round after defeating Radek Štěpánek, Dustin Brown and Feliciano López – losing to eventual champion Murray.

[61] In doubles, Kyrgios partnered with Jack Sock, defeating Tomas Berdych and Rafael Nadal and earning Team World's only point on Day 1.

[70] Kyrgios won the 2019 Mexican Open in Acapulco (his fifth title), after beating three top 10 players (i.e. Nadal, Isner and Zverev) and three-time Grand Slam champion Stan Wawrinka, en route.

In Rome, Kyrgios beat Daniil Medvedev but then lost his next match to Casper Ruud by default in the third set when he threw a chair on the court after swearing at a linesperson.

[72] At Wimbledon, Kyrgios defeated compatriot Jordan Thompson in a five-setter, but then lost to Nadal in four sets in the second round which was described as an entertaining encounter and a genuinely great match.

[99] At the 2022 Wimbledon Championships, Kyrgios beat wildcard Paul Jubb in 5 sets, but was fined US$10,000 for verbally abusing a line judge and spitting in the direction of a spectator.

[106] In Atlanta, Kyrgios withdrew from the singles tournament, but went on to win his second doubles title with Thanasi Kokkinakis, defeating fellow Australians Jason Kubler and John Peers in straight sets.

[111] In October, Kyrgios reached the quarterfinals of the Japan Open, but withdrew before his clash with Taylor Fritz, citing a knee problem as the cause for his exit.

[112] Kyrgios, along with doubles partner Thanasi Kokkinakis qualified for the 2022 ATP Finals in Turin after being guaranteed a spot under the Grand Slam champion provision.

[134] In an interview after the match Kyrgios was cautious about his upcoming participation in singles at the Australian Open stating that although doing well, his wrist needed more recovery work.

Despite Kyrgios calling the trainer to attend to a recent abdominal injury, he was unable to take it to a fourth set in front of a rowdy and supportive John Cain Arena.

[178][179] Kyrgios made his broadcasting debut as a guest commentator and analyst on Tennis Channel for the 2023 ATP Finals alongside Andy Roddick and Jim Courier.

The segment covered Kyrgios's mental health struggles and support from Andy Murray,[190] conflicts with other Australian athletes,[191] his return to tennis, his experience with racism,[192] and his mother being held at gunpoint.

"Lee McKenzie, who conducts immediate post-match interviews with winning players in front of the crowd on Centre Court at Wimbledon, was quoted as saying: "He is fascinating.

[223] Numerous top tennis players participated including Caroline Wozniacki, Serena Williams, Coco Gauff, Alexander Zverev, Stefanos Tsitsipas, Naomi Osaka, Dominic Thiem, Petra Kvitova, Novak Djokovic, Rafael Nadal and Roger Federer.

[225] In January 2021, Kyrgios called Djokovic a "tool" after he issued a wish-list of requirements for players forced to quarantine when they arrive in the country to play in the Australian Open.

[226] A year later, when Djokovic was detained by the Australian government after entering the country unvaccinated, Kyrgios was the first and most notable player to speak up for his predicament, declaring: "He's a human, I just don't think how we're going about it is the right way and that's coming from someone who we've had run in and comments about each other, but it's not right."

[230] At the 2019 Rome Masters, Kyrgios was defaulted from his second round encounter with Casper Ruud after swearing at a line judge, kicking a bottle, and hurling a chair onto court.

[231][232] The 2023 clay season was extremely rowdy and measures trialled at Roland Garros 2023 are being put in place to protect players from physical and social media abuse.

[246] In December 2021, Kyrgios started dating Psychological Sciences graduate Costeen Hatzi[247][248] who owns and runs several businesses in interior and dress design.