The oldest known mention of "Atlantic" is in The Histories of Herodotus around 450 BC (Hdt. 1.202.4): Atlantis thalassa (Greek: Ἀτλαντὶς θάλασσα; English: Sea of Atlas).[...]

The Atlantic Ocean was named by the ancient Greeks after either Atlas the Titan or the Atlas Mountains named for him;[4][5] both involve the concept of holding up the sky.