Jean-Baptiste Mac Nemara, baron du Mung, seigneur de la Rochecourbon, Tourfou, Moullet et autres lieux (circa 1690 — Rochefort, 18 October 1756)[1][2] was a French Navy officer of Irish origin.

His brother, Claude Matthieu Mac Nemara, had a career in the French Navy, rising to captain and to Knight in the Order of Saint-Louis.

[1] In 1713, when he married, Mac Nemara served as an Ensign in a company of the Navy and was Commissary for food at Rochefort arsenal.

Head of the Gardes-marines in Rochefort from 1 April 1745,[2] he also led a division in the Caribbean, fighting against FitzRoy Henry Lee and returning to France in 1746.

In 1756, he headed a 6-ship and 3-frigate squadron to bring reinforcements to Emmanuel Auguste Dubois de La Motte in New France (now Canada), comprising the ships Formidable, Héros, Palmier, Éveillé, Inflexible and Aigle, and the frigates Améthyste, Sirène and Héroïne, [7] and fought in the action of 8 June 1755.