The Idlib region is home to about three million people, around half of them displaced.
Children aged 10 to 14 have been training for months to take part in the "camps World Cup", said Ibrahim Sarmini from the NGO Violet, which organised the tournament.
He said the event aims to encourage children to participate in sports, and to "focus international attention on displaced youth and those who work", who are among those most exposed to sometimes deadly risks.
The last pocket of armed opposition to Bashar al-Assad's regime includes large swathes of Idlib province and parts of the neighbouring Aleppo, Hama and Latakia provinces.
The Hayat Tahrir al-Sham (HTS) militant group, led by Al-Qaeda's former Syria affiliate, is dominant in the area but other rebel groups are also active.
The "camps World Cup" matches will continue throughout the official tournament period, and the final will be organised in a camp in Idlib.
Sarmini noted that winter was set to begin in full force, with rains expected to once again bring misery to the ramshackle, poverty-stricken camps.
"I hope the whole world will turn their attention to the displaced and will support them so they can return to their homes as soon as possible," he said.
