The Champ de Mars (French pronunciation: ​[ʃɑ̃ də maʁs]; English: Field of Mars) is a large public greenspace in Paris, France, located in the seventh arrondissement, between the Eiffel Tower to the northwest and the École Militaire to the southeast. The park is named after the Campus Martius ("Mars Field") in Rome, a tribute to the Roman god of war. The name also alludes to the fact that the lawns here were formerly used as drilling and marching grounds by the French military.

The nearest Métro stations are La Motte-Picquet–Grenelle and École Militaire. Champ de Mars-Tour Eiffel, an RER suburban-commuter-railway station, is also Originally, the Champ de Mars was part of a large flat open area called Grenelle, which was reserved for market gardening. Citizens would claim small plots and exploit them by growing fruits, vegetables, and flowers for the local market. However, the plain of Grenelle was not an especially fertile place for farming.