1. Someone who portrays a victim in a training drill for emergency personnel, such as firefighters and EMTs. I volunteered to be a crisis actor at my local hospital's disaster drill.
2. conspiracy theory Someone who impersonates a victim of a tragic incident, typically a mass shooting, that has been staged. The concept originated with conspiracy theorists who claim that such actors are employed by governments or secret organizations attempting to stage such incidents to gain support for a particular agenda. The term gained widespread attention when some survivors of the February 2018 mass shooting at Marjory Stoneman Douglas High School in Parkland, Florida, were claimed to be crisis actors by conspiracy theorists in the aftermath of the shooting. Can you believe that some people think the Parkland kids were crisis actors paid to be there to further the liberal agenda on gun control? How sick is that?