This saturday morning market can be found on Rue Caulaincourt near Metro Lamarck-Caulaincourt in the 18th arrondissement. Although close to the Basilique du Sacre Coeur and the well-known charms of Montmartre this local market seemed pleasantly devoid of tourists. Not far from here the winding backstreets lead you to Rue des Saules, Rue Lepic, Rue des 3 Freres and around to Abbesses. Or you can visit the extremely popular Place du Tertre, home of portrait artists and tourist restaurants.
I think I prefer the street market on the quiet side of the hill.