Financial terms were not released.
The 18-year-old forward had 20 points (seven goals, 13 assists) in 21 games with HV71 of the SuperElit League in Sweden last season. He also won a gold medal with Sweden at the 2019 Under-18 World Championships, where he had six points (three goals, three assists) in seven games, which included a goal in the final game against Russia.
RELATED: [2019 NHL Draft first-round pick signings tracker]
Holmstrom missed the start of last season after having hip surgery, then injured his thumb shortly after his return. But he assured NHL.com during Islanders' development camp last month the injuries are not an issue.
"No problems at all," he said. "I'm all healthy."
---
Listen: New episode of NHL Draft Class presented by adidas