Legal Definition of Process server: A person who hands a summons or subpoena upon a witness or defendant | Need a Legal Process Server? Ensure that all parties involved in your legal case are properly notified and have the opportunity to respond or appear in court. Our professional process servers are responsible for delivering legal documents such as summonses and subpoenas. Learn more about the crucial role they play in the fair and efficient administration of justice. Contact us today for reliable and compliant document delivery