In 2013, after he had a dispute with the Dinamo board of directors,[7] Kramarić was transferred to HNK Rijeka, where he scored 37 times in 42 league games prior to his move to Leicester City for a record £9 million.

He took part at the 2010 UEFA European Under-19 Championship, making four appearances for a Croatian team that reached the tournament semi-finals.

He made his debut for the senior team in 2014, later taking part at three UEFA European Championships (in 2016, 2020 and 2024) and two FIFA World Cups (in 2018 and 2022), helping Croatia to reach the final of the 2018 tournament.

He made his first appearance of the season and also debuted in the UEFA Champions League on 15 July in an away match against Pyunik, which finished in a goalless draw.

[19] At Lokomotiva, he became one of the most proficient strikers in Southeast Europe, scoring 20 goals in 44 league appearances in the season-and-a-half he spent with the Lokosi.

In his first full season with Lokomotiva, he finished runner-up to Leon Benko in the Prva HNL top goalscorer race with 15 goals.

In July 2014, just before the start of the new season, Kramarić won the Croatian Supercup when Rijeka defeated his former club and reigning champions Dinamo Zagreb.

[34] The transfer, however, was dependent on Kramarić being awarded a work permit on appeal, as he did not meet the requirements for one to be automatically granted.

[36][37] On 16 January, Leicester announced Kramarić had officially joined the club after being granted a UK work permit and that he would wear the number 40.

[39] He made his debut the day after signing, replacing striker Jamie Vardy for the last 25 minutes of a 0–1 home defeat against Stoke City.

[43] He made his debut against Bayern Munich on 31 January, then scored his first goal in a draw with Werder Bremen, where he also was sent off in the 77th minute for accumulating two yellow cards.

Kramarić was considered one of Hoffenheim's key players in their 2016–17 campaign in which they finished fourth, alongside Niklas Süle, Sandro Wagner, Ádám Szalai, and Sebastian Rudy.

[47] On the last matchday, 27 June, he scored all four goals in a 4–0 away win against second-placed Borussia Dortmund, becoming the first Hoffenheim player to do so in a Bundesliga match.

[48] On 13 September, Kramarić scored both goals in a DFB-Pokal 2–2 draw with Chemnitzer FC, and successfully converted a penalty in a shootout as Hoffenheim won 3–2.

[55] On 24 January 2021, he surpassed Ivica Olić and became Bundesliga all-time top Croatian goalscorer after scoring a brace in a 3–0 victory over Köln and reaching the number of 74 goals.

[57] In the 2022–23 season, Kramarić reached two major milestones, scoring his 100th Bundesliga goal and providing his 50th assist for Hoffenheim in all competitions.

[58] On the final matchday of the 2023–24 season, he scored three goals in a 4–2 win over Bayern Munich, becoming the third player to achieve a flawless hat-trick for the club, following Ishak Belfodil and Vedad Ibišević.

He debuted and scored his first goal at under-21 level on 5 September 2009 in a European Championship qualifier against Norway, aged just 18 years and 81 days.

[66] On 9 October 2017, Kramarić scored two goals in a crucial 2018 FIFA World Cup qualifier against Ukraine, securing Croatia's qualification to playoffs.

[68] On 7 July, in the 2018 FIFA World Cup quarter-final match against hosts Russia, he scored Croatia's equaliser in the first half of regulation time.

[70] In the 2022 FIFA World Cup, Kramarić scored twice in a 4–1 win against Canada in the group stage,[71] as Croatia reached the semifinals and finished third.

[73] In the UEFA Euro 2024, he netted a goal in a 2–2 draw against Albania, becoming the third player to score in the tournament on his birthday following Jean-François Domergue in 1984 and Wesley Sneijder in 2008.

[78] On 31 March 2021, Kramarić married Mia Ćurković in a private ceremony at the Old City Hall in Zagreb Upper Town.