On 2 September 2019, Kalinić joined A.S. Roma on a season-long loan deal which includes an optional purchase clause. Kalinić was a key player in the Croatia national under-21 team during his youth playing years, also representing his country at the under-17 and -19 level. He first made a name for himself at international level at age 17 during the 2005 UEFA European Under-17 Championship when he finished the campaign as the top scorer with 11 goals. At the under-19 level, he managed another five goals during his side's preliminary round of the same tournament. He also scored a hat-trick against Lithuania in Croatia's 3–0 victory, which secured them a spot in the next elite round of the UEFA European Under-19 Championship in 2006. Initially supposed to be called up by head coach Slaven Bilić for the few remaining qualifying matches of UEFA Euro 2008, Kalinić missed the chance due to injury and was instead replaced by Mario Mandžukić. However, his constant impressive abilities earned him a place in Croatia's final squad for Euro 2008. He made his first appearance for the senior national team on 24 May 2008, coming on as a substitute in the 62nd minute of Croatia's 1–0 friendly win against Moldova. He went on to make his first competitive appearance for his national side at Euro 2008 in Croatia's final group match against Poland, coming on as a substitute for goalscorer Ivan Klasnić in the 1–0 victory. On 17 November 2010, Kalinić scored his first international goal, scoring the third goal in Croatia's 3–0 win at home to Malta in the Euro 2012 qualifiers. On 9 February 2011, he scored a brace in a 4–2 victory over the Czech Republic in an international friendly game. In June 2012, Kalinić replaced the injured Ivica Olić in Croatia's squad for Euro 2012 and remained an unused substitute in the tournament. Kalinić missed the 2014 World Cup, but received a call-up back for a friendly against Argentina in 2014, although he remained an unused substitute. In 2015, Kalinić returned to the international level. At Euro 2016, he scored a goal and assisted in a 2–1 victory in a group stage match against defending champions Spain. On 4 June 2018, Kalinić was named in Croatia's 23-man squad for the 2018 FIFA World Cup in Russia. On the fifth day of the tournament, he was sent home after refusing to come on as a late substitute during Croatia's first game of the competition against Nigeria, claiming to have a back injury, ending his international career.