Hugely popular English name, comes from Hebrew (שמואל) [Shemu'el] denotation - "God (El) has heard; God has hearkened; name of the God". See the name Ishmael.
Samuel was the last of the ruling judges in the Old Testament. He anointed Saul to be the first king of Israel, and later anointed David. As a Christian name, Samuel came into common use after the Protestant Reformation. Arabic form - Ismail.