Pierre Lyonnet or Lyonet (21 July 1706 – 10 January 1789) was an artist and engraver who became a naturalist. He was a collector both of shells (a major collecting craze at the time) and paintings, whose collection included Woman Reading a Letter by Vermeer, now in the Rijksmuseum. This fetched far less than his best shells in the auctions of his collection after his death.