Jacob is derived from Late Latin Iacobus, from Greek Ἰάκωβος Iakobos, from Hebrew יַעֲקֹב (Yaʿqob, Yaʿaqov, Yaʿăqōḇ), the name of the Hebrew patriarch, Jacob son of Isaac. It is a speaking name, referring to the circumstances of Jacob's birth, meaning ‘heel-grabber’ (from the Hebrew root עקב ʿqb ‘heel’; literally, it is a finite verb formed from this root, and would translate to something like ‘he heeled’), since he held on to the heel of his twin brother Esau inside Rebekah's womb. Jaakob may also mean ‘follower of God’ in Aramaic. In a Christian context, the name Jacob — as James in English — is also associated with the apostles James, son of Zebedee who was the object of great veneration in the European Middle Ages, notably at Santiago de Compostela; James the Just, brother of Jesus, who led the original Christian community in Jerusalem; and James, son of Alphaeus.

The name James came into English language from the Old French variation James or Gemmes of the late Latin name, Iacomus; a dialect variant of Iacobus.