Porte Sainte-Croix, Triumphal arch in Châlons-en-Champagne, France

Porte Sainte-Croix is a triumphal arch of pale stone built in 1770, measuring 19.50 m wide and 17.25 m high, with an archway 11.25 m high and 4.90 m wide. Its south facade, facing the Strasbourg road, carries two trophies carved by the sculptor Lépine. The north facade has two niches for reliefs of Mars and Minerva that were never completed.

The gate was built in 1770 to replace the city's medieval fortifications with a monumental entrance structure. It marked the shift from medieval to modern urban design in the final years before the French Revolution.

The name Sainte-Croix likely comes from a nearby chapel, destroyed later, not from a church still standing. From 1770 until the Revolution the arch was called Porte Dauphine, dedicated to Marie-Antoinette, who entered Châlons through it on 11 May 1770 and attended a fireworks display by the Parisian pyrotechnist Bray.

The gate stands at the western edge of the town center and is easily visible and accessible from the street. It is best visited on foot as part of a walk through the old town to fully appreciate the neoclassical details up close.

The two bas-reliefs of Mars and Minerva in the upper niches of the north facade were sketched out, but the finishing work was to be done by Jean-Baptiste Pigalle. No trace of these statues survives; some authors believe they were temporary decorations made for Marie-Antoinette's passage on 11 May 1770.