Prince Danilo I Petrović-Njegoš (May 25, 1826, Njeguši, Montenegro – August 13, 1860, Kotor, Austria in today's Montenegro), son of Stiepo/Sava Petrović-Njegoš and wife Angelika Radamovich, is the prince-bishop and later prince of Montenegro from 1851 to 1860.
During his reign, Montenegro becomes a secular state, a lay principality instead of a bishopric-principality.
He becomes involved in a war with the Ottoman Empire in 1852, the Porte claiming jurisdiction in Montenegro, and the boundaries between the two countries are not defined until 1858.
Danilo, with the help of his elder brother, Duke Mirko, defeats the Ottomans at in 1853 and in the Battle of Grahovac in 1858.
On January 12, 1855 at Njegoš he marries Darinka Kvekić, who was born in a wealthy Serbian merchant family in Trieste on December 31, 1837 and dies on February 14, 1892), daughter of Marko Kvekić.