The Vaasa riot took place on 4 June 1930 in Vaasa, Finland. The riot unfolded with a violent attack by radical members of the right wing Lapua Movement on Communist supporters and bystanders at a court house in Vaasa.

n. 1) technically a turbulent and violent disturbance of peace by three or more people acting together. 2) an assemblage of people who are out of control, causing injury or endangering the physical safety of others and/or themselves, causing or threatening damage to property and often violating various laws both individually and as a group. The common thread is that the people in a riot have the power through violence to break the public peace and safety, requiring police action. Often a riot is declared after the crowd has been informed by police officers that the people constitute an "unlawful assembly" and are ordered to "disperse" immediately (historically in England called "reading the riot act"). If the crowd does not disperse, its members become subject to arrest for the crime of rioting, disturbing the peace, resisting arrest or other separate crimes ranging from assault to unlawful possession of firearms.