The middle name in Marie Curie's birth name, Maria Salomea Skłodowska, is Salomea. She was born in Warsaw on 7 November 1867 and later became widely known in France as Marie Curie.
“Maria” was her given name in Polish usage, while “Salomea” was an additional baptismal or middle name. After moving to Paris for higher education, she used the French form “Marie.” Her surname Skłodowska remained central to her identity, and after marrying Pierre Curie she became known as Marie Skłodowska-Curie.
The name also reflects Curie's continuing connection to Poland. She named polonium, one of the elements she discovered with Pierre, after Poland. Although she became a French citizen and built much of her career in France, she retained her Polish identity and used both surnames in public and scientific contexts.