The men were sentenced to between nine and 14 months in jail for “causing public disorder and deliberately damaging property”, the People’s Court of Nhon Trach district in Dong Nai province said.
The men took part in an anti-China protest on May 13, and then vandalised businesses operating in Nhon Trach Industrial Park near Ho Chi Minh City, causing damage to 10 foreign-owned companies.
The defendants confessed and showed remorse, the court said.
The protests across Vietnam were triggered by the deployment of a Chinese oil-drilling platform in seas also claimed by Vietnam. Beijing eventually moved the rig in July. Around 200 people were arrested for taking part in riots in industrial zones across the country.
Nearly 120 were found guilty and 50 have been given jail terms. About 100 factories suffered damage, including 15 that were completely destroyed.