Cam Newton got his first-EVER tattoo earlier this week on his left hand ... but the Carolina Panthers superstar played it cool leaving the shop -- hiding the new ink in his swaggy jacket!!
TMZ Sports has learned Cam hit up Bang Bang Grand in New York City to get the piece done ... and, per a source, the art is engraved somewhere on his non-throwing hand. You can see the bandage in the post-sesh pic he took with his tattoo artist, Bang Bang.
But, the QB ain't ready to show off the work just yet .