Insigne has been the target of jeers and boos from some of the San Paolo faithful following an inconsistent campaign to date, in which he has managed just one goal in 22 Serie A appearances.
However, former Partenopei star Maradona believes supporters should get behind the Italy international as he looks to improve his form for his boyhood club.
"Lorenzo Insigne? I really like him," Maradona told Il Mattino. "I'm sorry that the fans are booing him.
"I love Lorenzo - he is a street urchin. Fans need to understand that players like us, who are looking for the goals, should be encouraged by the fans forever."
Insigne, who has played 31 times in all competitions for Rafa Benitez's side this season, is currently preparing with the squad for Wednesday's Coppa Italia clash with Roma.