The Islanders did not release the financial terms of the agreement.
Dal Colle, 23, recorded three goals and four assists in 28 games last season.
The six-foot-two, 198-pound winger, who was selected with the fifth pick in the 2014 NHL Draft, has seen his stock drop significantly since he was selected.
Dal Colle, a native of Woodbridge, Ont., has only logged 32 games at the NHL level. However, he had his best season yet in the minors in 2018-19, putting up 34 points in 34 games with the Islanders’ AHL affiliate in Bridgeport. He was named to the league’s All-Star Game for his efforts.