He was born in Reims and at age eighteen went to Paris to study at the École des Beaux-Arts. A student of François Jouffroy, he became primarily a sculptor of portrait busts and animals. He exhibited at the Paris salon from 1868, when, passing up the competition for the Prix de Rome, he decided to spend time in Florence instead. He passed a second sojourn in Italy in 1873-74. On his return, his marble Génie gardant le secret de la tombe ("Spirit Guarding the Secret of the Tomb"), conserved in the Musée d'Orsay, Paris, shows the marked influence of Michelangelo.
In 1891 René de Saint-Marceaux joined the newly formed Société des artistes français.
His bronze and granite monument for the headquarters of the Universal Postal Union in Bern, Switzerland (illustration) erected in 1909, represents the five continents as floating figures joined in transmitting messages around the globe. A postage stamp honoring the sculptor and the monument was issued jointly by Switzerland and France in 2009.
René de Saint-Marceaux died in Paris in 1915.