Mercédès Legrand was born on 14 July 1893, Almodóvar del Campo, Castilla–La Mancha, Spain to Belgian parents.

[2] The first ten years of her childhood were spent in Spain, before she moved abroad to Brussels, Belgium, England and Germany for schooling.

In September 1920, Legrand completed a World War I memorial in Nassogne, Belgium, commissioned by the municipality, and is depicting a civilian confronted with the remains of a soldier.

[4] Legrand, Van Gindertael, and Michel de Goeye co-created Hélianthe, an avant-garde arts review magazine.

[2] In Paris, she exhibited regularly artists such as Jean Pougny, Emmanuel Mané-Katz, Raoul Dufy, Edouard Vuillard, Georges Rouault, Othon Friesz, and André Lhote.