Natalija Konstantinović (Serbian Cyrillic: Наталија Константиновић; 10 October 1882 – 21 August 1950) was a Princess of Montenegro, as the wife of Prince Mirko Petrović-Njegoš.

Prior to the assassination, the conspirators had voted to pass the crown to Mirko's brother-in-law, Peter, the head of the rival Serbian dynasty, the Karađorđevićs.

This was because the Karađorđevićs were allied with Russia, whereas the Obrenovićs were decidedly pro-Habsburg,[5] and therefore distasteful to many Serbs in light of the fervent Pan-Slavic nationalism that had engulfed Serbia since the 19th century.

In 1916, the defence of Montenegro collapsed when the Austro-Hungarian forces invaded the kingdom during World War I, and the entire royal family, including Natalija, was compelled to flee to Italy.

The following year, Mirko died in Vienna and her eldest surviving son Michael became head of the House of Petrović-Njegoš and pretender to the defunct throne of Montenegro.

They met in Belgrade while his father, Gaston Errembault de Dudzeele has served as Belgian ambassador to the Kingdom of Serbia and became romantiaclly involved prior to her first politically arranged marriage.