Black Pete is often played by white people with their faces daubed in dark makeup. He has been at the center of fierce debate for years between supporters who see him as a traditional children's character and opponents who decry him as a racist stereotype.
Those convicted were ordered to do unpaid community work and the ringleader was given a suspended one-month prison sentence. The court in the northern city of Leeuwarden said in a statement that by blocking the highway last year, they "took the law into their own hands" to infringe protesters' constitutional right to demonstrate.
Lawyers representing the anti-racism demonstrators welcomed the ruling, saying in a written statement that it "sent a signal that citizens in a democratic society cannot play judge."
The ruling came just over a week before this year's nationally televised parade to welcome the Dutch character Sinterklaas to the country for a festive period that ends on Dec. 5 when families traditionally exchange gifts.
Smaller Sinterklaas parades are scheduled across the country next weekend and protests both for and against Black Pete are expected at a handful of them.
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.