Lewis Morris (2 March 1701 – 11 April 1765) was a Welsh hydrographer, antiquary, poet and lexicographer, the eldest of the Morris brothers of Anglesey. Lewis Morris was the eldest son of Morris ap Rhisiart Morris, a farmer, of Llanfihangel-Tre'r-Beirdd in Anglesey. His bardic name was Llewelyn Ddu o Fôn ("Black Llewelyn [Lewis] of Anglesey"). The correspondence between him and his younger brothers is a valuable historical source. In 1751, he founded the Honourable Society of Cymmrodorion along with his brother Richard.