Involuntary Actions are those actions in our body that are not controlled by our will. For example, heartbeat rate, digestion, etc. These are generally controlled by our brain.
& Reflex actions are spontaneous, automatic and mechanical responseto a stimulus action on a specific receptor without the will of an animal. For example, removal of our hand in a hurry whenever we touch a hot object by mistake. These are mainly controlled by spinal cord to fasten the reaction.