Square Marcel-Bleustein-Blanchet, Urban park near Sacré-Coeur, Montmartre, France.

Square Marcel-Bleustein-Blanchet is an urban park in the 18th arrondissement of Paris that rises across terraced levels on a sloped site. The space features stone seating beneath a wisteria-covered pergola, a small cascade fountain, an amphitheater, and mature trees including a significant plane tree.

The site once held the Moulin de la Turlure, a grain-processing mill that operated between 1770 and 1820 during Paris's industrial period. This mill was eventually replaced by the park, which transformed the location into a public gathering space.

The square honors Marcel Bleustein-Blanchet, a French resistance member and founder of Publicis Group, through its name since 2004. This dedication reflects the neighborhood's connection to figures who shaped modern French culture and business.

Enter from 1, rue de la Bonne, at the corner with rue du Chevalier-de-La-Barre; metro line 12 stops at Lamarck-Caulaincourt. The 14 m slope is split into terraces: the Grand Salon and wisteria-covered walk sit at the top, the children's area, two climbing walls and the boulodrome at the bottom. Drinking water and public toilets are on site.

The park's most notable tree is a common plane tree 27 m tall with a 3.5 m circumference, a species typical of Second Empire planting programmes. It leans east toward the park's panorama over eastern Paris. The architect Antoine Grumbach kept many older trees on the site, including maples, wild cherries, catalpas, lindens and magnolias.