Princess Marcelina Czartoryska, née Radziwiłł (Podłużne, 18 May 1817 − 5 June 1894, Kraków) was a prominent Polish aristocrat and pianist.

Born into the mighty Polish magnate family, the Radziwiłłs, in 1840 she married Aleksander Czartoryski, an aristocrat from a family of no lesser notability.

She was taught piano by Carl Czerny in Vienna and by Frédéric Chopin in Paris. She gave concerts across Europe, often with prominent musicians such as Franz Liszt, Pauline Viardot and Henri Vieuxtemps.

In Paris she became a prominent guest at the Hôtel Lambert, bought by Prince Adam Jerzy Czartoryski, a close relative of her husband Aleksander. In 1849 she was present at the deathbed of her teacher and friend, Frédéric Chopin.

From 1870 she lived in Kraków, where she gave mainly private concerts and, thanks to her artistic connections, contributed to founding a Conservatory in 1888. She died in 1894 and was buried at the Rakowicki Cemetery.