Born in Carrara, Tuscany, Belloni played for nearby team Spezia prior to joining Serie A club Internazionale in 2008. On 17 April 2013, Belloni came on as a late substitute replacing Andrea Ranocchia in the 87th minute in 2012–13 Coppa Italia semi-final loss against Roma to make his debut.
On 23 July 2013 he joined Serie B club Modena in a co-ownership deal. On 24 September he made his debut for Modena in Serie B in a match against Crotone, he enter as a substitute replacing Salvatore Molina in the 51st minute, after only 3 minute Belloni score his first and only goal for Modena in a 3-1 away defeat.
On 21 July 2014, Belloni was signed by Serie B club Pro Vercelli on loan. Belloni made his debut on 17 August in the second round of Coppa Italia, he was replaced by Abdouramane Coly in the 59th minute of a 2–1 away defeat against Brescia. He made his Serie B debut on 30 August, as a substitute, replacing Gianni Fabiano in the 66th minute in a 1–0 away defeat against Avellino. On 7 September he score his first goal for Pro Vercelli in the 72nd minute of a 3–2 home win over Catania. On 20 September, Belloni played his first entire match for Pro Vercelli, a 4–0 home win against Varese. On 13 December, Belloni score his second goal for the club and the winning goal in the 86th minute of a 1–0 away win against Crotone. Belloni ended his season-long loan to Pro Vercelli with 36 appearances, 2 goals and 1 assist.
On 13 August 2015, Belloni was loaned to Serie B club Ternana with a season-long loan. On 21 September, Belloni made his debut, as a starter, and score his first goal with Ternana on in the 31st minute of a 3–2 home defeat against Livorno, he was replaced by Cesar Falletti in the 82nd minute. On 17 October, Belloni play his 50th professional match and score his second goal for Ternana in the 25th minute of a 3–0 win over Bari. Belloni ended his season-long loan to Ternana with 20 appearances and scoring 2 goals, but he never play an entire 90 minute match.
Loan to Avellino
On 1 July 2016, Belloni signed for Serie B club Avellino with a season-long loan. On 27 August, Belloni made his debut for Avellino, he was replaced by Daniele Verde in the 75th minute of a 1–1 away draw against Brescia. On 4 September, Belloni played his first full match for Avellino,a 2–0 away defeat against Virus Entella. On 17 September he score his first and only goal for Avellino in 3–1 away defeat against Hellas Verona. On 24 December, Belloni was sent off with a double yellow card in the 68th minute of a 3–2 home win over Salernitana. Belloni ended his loan to Avellino with 30 appearances, 1 goal and 1 assist.
On 31 August 2017 he signed with Serie B club Carpi with a season-long loan. On 19 September, Belloni made his debut for Carpi, as a starter, in a 3–1 home defeat against Foggia in Serie B, he was replaced by Fabio Concas in the 51st minute. Belloni ended his loan to Carpi with only 11 appearances, all in the first part of the season and he never played an entire match in this loan.
Arezzo
On 21 August 2018, Belloni moved to Serie C club Arezzo on permanent deal.
