Pieter Jacobus (Piet) Meertens (Middelburg, 6 September 1899 – Amstelveen, 28 October 1985) was a Dutch scholar of literature, dialects, and ethnology. He founded the institutes which later merged into the Meertens Instituut (a research institute operated by the Royal Netherlands Academy of Arts and Sciences), of which he was the director until 1965.