Objective: The objective of this study was to determine the level of social support and associated factors in selected prison institutions in Amhara region, Ethiopia. Result: Prisoners that had good social support from their family, friends, and significant others were 64.7%, (95% CI 60.9%, 68.4%). The odds of social support was higher among those educated and rural prisoners. However, it was found to be lower among non-Orthodox Christian prisoners and prisoners who were discriminated. Social support is buffering tool for social difficulties and hardships faced by prisoners while they are in prison and very helpful to reduce mental health morbidities and their consequences, hence should be strengthened.