After graduating Takigawa Daini High School in 2004, Okazaki signed full professional terms withShimizu S-Pulse the following year. In December 2005, he made his firstJ.League appearance as a substitute againstSanfrecce Hiroshima. On 15 April 2007, he scored his first professional goal againstKawasaki Frontale. Okazaki ended hisfirst season as a first team player with three goals from 13 matches.
On 30 January 2011, Okazaki signed a three-and-a-half-year contract with Stuttgart.[5] On 17 February 2011, clearance to play for the club was granted for Okazaki byFIFA.[6] He made his competitive debut for VfB on the same night in aEuropa League match againstBenfica. On 20 February 2011, Okazaki made hisBundesliga debut for VfB againstBayer 04 Leverkusen. Okazaki scored his first goal againstHannover 96, which he scored from outside the box.[7]
Okazaki came on as a second-half substitute for Stuttgart in their first game of the2011–12 Bundesliga season againstSchalke 04. His side were up 2–0 and Okazaki added a goal scoring from long range in the 90th minute, sealing a 3–0 win.[8] Okazaki's goal from a bicycle kick on 19 February 2012 in a Bundesliga match of VfB Stuttgart against Hannover 96 was selectedGoal of the Month. AfterYasuhiko Okudera in April 1978, Okazaki was the second player from Japan to win this award in Germany.[9]
Okazaki had a poor2012–13 season, scoring only once in theBundesliga. However, he scored his first goals in European competition with two goals againstSteaua București in theEuropa League.
On 1 July 2013, Okazaki moved toMainz 05.[10] He scored his first goal for Mainz on his debut in a 3–2 win against his former club Stuttgart on the opening matchday of the2013–14 Bundesliga season.[11] At the end of the season he ended with 15 league goals.
Okazaki became the most prolific Japanese player in Bundesliga history on 13 September 2014, scoring his 27th and 28th league goals in Mainz's 3–1 win overHertha Berlin.[12]
He made his debut for the club on 8 August 2015 in Leicester City's 4–2 opening day win againstSunderland, and scored his first goal for the club the following week in a 2–1 win againstWest Ham United. On 19 December 2015, Okazaki scored the winner in a 3–2 win overEverton atGoodison Park, to ensure that Leicester City topped the table at Christmas.[14]
On 10 January 2016, Okazaki scored Leicester's second goal in theFA Cup clash atWhite Hart Lane withTottenham Hotspur despite drawing to aHarry Kane penalty in the 90th minute. On 14 March 2016, Okazaki scored in a league fixture againstNewcastle United: a spectacular overhead strike that won Leicester City the game 1–0 and took them five points clear at the top of the Premier League table.[15] Leicester City went on to win the league that year, making Okazaki the second Japanese player to win the Premier League afterShinji Kagawa.[16]
Okazaki scored twice in a 2–4 defeat to Chelsea in the third round of the 2016–17EFL Cup on 20 September 2016.[18] He scored his first league goal of the season in a 3–1 win overCrystal Palace on 22 October 2016, earning himMan of the match and achieving an 84.8% pass success rate, more than any other Leicester player.[19] On 22 November 2016, Okazaki scored in a 2–1 win overClub Brugge in theChampions League group stage, becoming the sixth Japanese player to score aChampions League goal and the first sinceKeisuke Honda in November 2013.[20] He finished the season with only three league goals.[21]
Okazaki was in goalscoring form at the start to the2017–18 season, scoring four goals in six appearances for Leicester in all competitions.[22] He was released by Leicester at the end of the 2018–19 season.[23]
On 30 July 2019, Okazaki signed a one-year contract withMálaga CF.[24][25] However, Málaga canceled its contract with Okazaki after just 34 days, since his wage demands exceeded its maximum budget as permitted by the league.[26]
On 4 September 2019, thefree agent Okazaki signed a one-year contract withSegunda División sideHuesca.[27] On 8 September 2019, he made his debut for Huesca as a substitute.
On 25 July 2020, after scoring 12 times as his sideachieved promotion toLa Liga, Okazaki renewed his contract for a further year.[28]
On 19 August 2022, Okazaki signed withSint-Truiden in Belgium. On 26 February 2024, he announced he would retire from playing at the end of the 2023–24 season.[30]
In October 2009, Okazaki scoredhat-tricks in consecutive matches as Japan beatHong Kong andTogo 6–0 and 5–0 respectively.[31] He was named The World's Top Goal Scorer of 2009 by theIFFHS for his 15 goals with the national team.[32]
Okazaki scored twice at the2013 FIFA Confederations Cup, againstItaly andMexico respectively. However, Japan lost all three of its matches and was eliminated at the end of the group stage.[34]
In June 2014, Okazaki was selected in the Japan's squad for the 2014 FIFA World Cup.[35] In the team's third group match, a 4–1 defeat toColombia, he scored Samurai Blue's only goal with a header in the 45th minute.[36]
Okazaki was included in Japan's squad for the2015 AFC Asian Cup and scored in a 4–0 defeat ofPalestine during the group stage.[37]
In March 2016 Okazaki was presented with a commemorative shirt with 100 on the back in a presentation to celebrate his 100th international appearance for Japan.[38]
Okazaki is currently the top active Japan national team goalscorer and third all-time in team history with50 international goals.[39]
Okazaki co-founded the German football club Basara Mainz in the 2014–15 season when he was a player ofMainz 05.[40] Now he serves as the club adviser. The club is run by the other co-founder, Takashi Yamashita, former player of Mainz's reserve teamMainz 05 II. Basara Mainz started in tier 11 of theGerman football league system. It was promoted to tier 6,Verbandsliga Südwest, in 2019.[41][42]