[3] After playing for the Napoli Primavera side in the club's youth system,[4][5][6] he made his professional debut for the club's senior side under manager Walter Mazzarri in the Europa League on 6 December 2012, in a 2–0 home defeat against PSV Eindhoven;[6][7] his first appearance in Serie A came on 13 January 2013, as he appeared as a very late substitute in a 3–0 home win against Palermo, playing alongside his older brother.

[9] On 15 July 2015, both Insigne and his young Napoli attacking teammate Gennaro Tutino were sent on loan to Avellino with an option to buy.

It was also only the second time in Serie A history that two brothers have scored against each other in a game; Hungarian pair István and Ferenc Nyers did the same back in 1949, while playing for Inter Milan and Lazio respectively.

[20] Regarded as a talented and promising prospect, Insigne is a diminutive, quick, creative, and skilful left footed forward, with good technique, an eye for goal, and a small, slender physical build, who is capable of playing anywhere along the front line.

[4][6][21][22][23][24][25] Perugia Benevento Frosinone Roberto is the younger brother of footballer Lorenzo Insigne, who plays for Toronto FC.