[5][6] After coming up through Hrvatski Dragovoljac's youth ranks, Brozović appeared in 22 games for his boyhood club in 2011, a season which saw the side relegated.

[9] He was given squad number 77, and made his competitive debut on 14 September in the goalless draw against NK Osijek at home, appearing as a second-half substitute.

[10] Four days later, Brozović made his UEFA Champions League debut by playing full-90 minutes in a 0–2 home defeat to Porto in the matchday 1 of group stage.

[22] On 7 February of the following year, he assisted Jeison Murillo's goal from a corner kick in the match against Hellas Verona, which finished in a 3–3 away draw.

[27] On 15 September, during the first match of 2016–17 UEFA Europa League group stage against Hapoel Be'er Sheva, Brozović played as a starter before was substituted in the beginning of the second half; he refused to stay in the bench which created controversies at Inter.

[30] He was finally called back on 20 October for the league match against Cagliari,[31] finished in a 1–2 home defeat, remaining as an unused substitute.

[32] Four days later, he made his on-field debut in the matchday 3 of 2016–17 UEFA Europa League group stage against Southampton, but was sent off in the 77th minute after receiving a second yellow card.

[33] Brozović improved his game with the new coach Stefano Pioli,[34] scoring his first goal of the season on 24 November in the 3–2 away defeat to Hapoel Be'er Sheva, despite being 2–0 up in the first half, which confirmed the elimination of Inter from Europa League.

[35] That was followed by his first league goal four days later, scoring inside two minutes with a right shoot from edge the box, helping Inter past Fiorentina 4–2 at San Siro.

[39] Later on 11 February of the following year, during the league match versus Bologna, Brozović was replaced in 58th minute after a poor performance; while making his way out of the field, he was booed by some sections of the crowd, and he responded by sarcastically clapping back.

[47] In the 2018–19 season, Brozović made his first UEFA Champions League appearance for Inter on 18 September in the opening Group B match in a 2–1 comeback win versus Tottenham Hotspur.

[52] On 17 August, in a Europa League semi-final, he provided Danilo D'Ambrosio with an assist for the second goal in a 5–0 victory over Shakhtar Donetsk at Merkur Spiel-Arena.

[54] On 2 May 2021, four matchdays before the end of the season, Sassuolo drew 1–1 with Atalanta at home, meaning that Inter mathematically secured the Serie A title.

[58] On 27 August 2021, in a 3–1 league victory over Hellas Verona, Brozović made his 200th Serie A appearance, becoming the first Croatian to achieve that in the three-points-for-a-win era.

[60] Inter, however, lost the game 1–0 to Manchester City, interrupting the streak of Croatian players winning the Champions League that went back to 2013.

On 31 May 2014, Brozović was included in Niko Kovač's final list for 2014 FIFA World Cup,[65] and made his debut for the main squad on 7 June, starting in a 1–0 success against Australia at the Estádio de Pituaçu.

[68] His second goal of the Euro 2016 qualifiers came in March 2015 against Norway, when he gave his team a 1–0 lead with a low curving shot from 20 meters into the bottom right corner.

[70] He made his first UEFA European Championship appearance in Croatia's first match of Group D versus Turkey, playing full 90 minutes as the team won 1–0.