A product of Inter Milan's youth academy, Dimarco made his debut for the club on 11 December 2014, aged 17, when he came on as a substitute for Danilo D'Ambrosio after 84 minutes in a goalless draw away to Qarabağ in the group stage of the UEFA Europa League, with his team having already advanced. He was called up for a Serie A match for the first time on 1 February 2015, remaining an unused substitute in a 1-3 defeat away to Sassuolo. Dimarco made his debut in Serie A on 31 May 2015, in the last match of the season in what would be a 4–3 win over Empoli, coming on in place of Rodrigo Palacio in the 89th minute of the game.
In January 2016 he was sent on loan to Serie B club Ascoli with a 6-month loan deal. On 6 February, Dimarco made his debut for Ascoli in Serie B in a 0-0 home draw against Latina, he was replaced by Dario Del Fabro in the 81st minute. Dimarco finish his 6-month loan to Ascoli with 15 appearances and 4 assists.
Loan to Empoli
He was sent on loan to Serie A club Empoli with a season-long loan deal. On 28 August 2016 he made his debut for Empoli in Serie A in a 2-0 away defeat against Udinese, he was replaced by Marco Zambelli in the 69th minute. On 29 November, Dimarco in the fourth round of the Coppa Italia in a match loss 2-1 in the extra time against Cesena. He finish his season-long loan to Empoli with 13 appearances, but Empoli was relegated in Serie B.
On 30 June 2017, Dimarco was sold to Sion for a fee of €3.91 million. On 23 July 2017 he made his debut for Sion in the Swiss Super League in a 1-0 away win over Thun, he was replaced by Quentin Maceirais in the 41st minute for a fracture of the foot.
On 5 July 2018, Inter exercised their buy-back clause to bring back Dimarco for €7 million. On 7 August 2018, Dimarco was loaned to Parma with an option to buy. He made his debut for Parma on 12 August in the third round of Coppa Italia, a 1–0 loss to Pisa. On 16 September, he scored his first goal in Serie A in a 1–0 win against Inter at San Siro. On 31 January 2020, Dimarco moved to Hellas Verona on loan until the end of the season with an option for a permanent move.
Considered to be a promising young prospect, Dimarco is a left-footed defender who usually plays as a left-back, although he is also capable of playing on the right. He is known in particular for his pace, tireless running, eye for goal, and his powerful and accurate shot, as well as his ability to interpret the game, which enables him to aid his team both defensively and offensively. In spite of his small stature and slender physique, he possesses significant strength and good technical skills.
