Marie Louise was born in Rome on 17 January 1870 as Maria Luisa Pia Teresa Anna Ferdinanda Francesca Antonietta Margherita Giuseppina Carolina Bianca Lucia Apollonia di Borbone-Parma, the eldest daughter of Robert I, Duke of Parma, and Princess Maria Pia of Bourbon-Two Sicilies.

Princess Clémentine, who was present on that occasion, described her future daughter-in-law in a letter to Queen Victoria as "Unhappily not very pretty, it is the only thing which is lacking, since she is charming, good, very witty, intelligent and very likable".

The couple wasted no time producing an heir, with their son Boris born nine months and ten days after their wedding.

Under pressure from his subjects and looking to be recognized as Bulgaria's sovereign by the Russian emperor, Ferdinand wanted to have their eldest son, Boris, converted to the Bulgarian Orthodox Church in the summer of 1895.

However, unable to avoid Boris's conversion, Marie Louise, who had threatened to leave the country, left Sofia that same day for Beaulieu.

In the summer, she went to London with her husband for Queen Victoria's Diamond Jubilee, giving birth the following January to Princess Eudoxia.