Square de l’Île-de-France, Urban garden near Notre-Dame Cathedral in 4th arrondissement, France.

Square de l'Île-de-France is a flat lawn of 2,235 m² at the eastern tip of Île de la Cité, behind Notre-Dame, enclosed by a low green metal fence and dotted with small white flowers. Bare-branched trees stand on one side; beyond the fence a paved walkway and a raised stone terrace with stairs and a metal railing lead to the Mémorial des martyrs de la déportation, whose entrance is through the square.

The location was once home to a 19th-century morgue building that served the city's administrative needs. This site was transformed into a public garden in the early 20th century.

The square takes its name from the region of Île-de-France and gives access to the Mémorial des Martyrs de la Déportation, built 1954–1964 at its south-western corner. The memorial entrance is reached through the garden, so a visit to the lawns and the memorial is a single stop behind Notre-Dame.

The square lies at the eastern tip of Île de la Cité, east of the quai de l'Archevêché, and the entrance to the Mémorial des Martyrs de la Déportation is through it. Métro line 4 stops at Cité, line 10 at Maubert - Mutualité, and RER B and C at Saint-Michel - Notre-Dame. The square closed at the end of August 2026 for redevelopment work.

The square's name refers to the Île-de-France region, not to the island itself. Its 2,235 m² were laid out in 1914 on the site of the 1868 morgue, whose entrance, shaped like a small Greek temple, opened onto the square. The Mémorial des martyrs de la déportation was built at its south-western corner from 1954 to 1964, and visitors enter the memorial through the square.