Starobilsk (Ukrainian: Старобільськ, lit. 'Old Bilsk'; Russian: Старобельск, romanized: Starobelsk) is a city in Luhansk Oblast, Ukraine. It serves as the administrative center of Starobilsk Raion. The modern settlement was founded in 1686, and it was granted city status in 1938. The city has a population of 15,947 (2022 estimate). As a result of the Russian invasion of Ukraine, it has been under Russian occupation since 28 February 2022.

Presumably, Starobilsk traces its heritage to the settlement of Bielska Sloboda which originally might have been named after Okolnichy Bogdan Belsky of Litvin Bielsky family who at that time was a subject of the Grand Duchy of Moscow.^{[citation needed]}

Bielsky arrived at the banks of Siversky Donets to build a fortress at the southern borders Tsare-Borisov (after Muscovite Tsar Boris Godunov) which was erected not far away in 1598–1600. In 1602 Godunov became suspicious of Belsky and order him to be arrested, stripped of any estates, and exiled to Siberia. After the death of Godunov Belsky was granted amnesty in 1605 due to the fact that his sister being the wife of the deceased Boris Godunov, Maria Skuratova-Belskaya, became a regent. Belsky was sent as a voivode to Kazan where in 1611 was killed by a mob after refusing to pledge allegiance to False Dmitry II. Sloboda gradually became abandoned, while the fortress was destroyed in 1612 in one of the Tatar raids.

In 1686 the settlement was repopulated by servicemen of the Ostrohozk Sloboda Cossack Regiment who originally came from Poltava and Chernihiv regions and named their settlement after a town of Bilsk, Cossack Hetmanate that might have belonged to another Litvin who sided with Muscovites, Theodore Bielsky.

Being runaway serfs, the Tsarist government allowed them to settle in the military frontier with the Crimean realm to carry out border guard functions. After the place became populated with serfs from the central regions of today's Russia, the Tsarist government took measures to find and return those fugitives. In 1701 the Ambassadorial Prikaz decided to conduct a population census in new settlements along Aidar and Siversky Donets. Most population avoided the census. According to data of stolnik M.Pushkin who in 1703 conducted a population census in 34 settlements, in Bielsky was registered only 41 residents although in reality there were much more.

Trying to meet the demands of Russian landlords who repeatedly turned to the Tsar with complaints and requests to return fugitives, on 6 July 1707 Peter the Great issued an edict (ukase) about the search of "newly arrived from Rus all ranks of people". To the Don was sent a punitive detachment under the command of Colonel Prince Yuriy Dolgorukiy. He was charged to search for fugitives and "take them to those landowners from whom they ran away". That action led to the well-known Bulavin Rebellion. Struggling with the rebellion, Tsarist troops eventually burnt the settlement to the ground.

In 1732 the settlement was repopulated again by peasants from around Ostrogozhsk (Ostrohozk) turning it into a sloboda Stara-Bila. Among the first of its new residents were again servicemen of the Ostrohozk Regiment led by sotnik I. Senelnykov. In 1782 Staro-Bila was assigned to the Derkul Horse Factory of Bilovodsk district (Voronezh Governorate). On Tsarist edict (ukase) from 1 May 1797 sloboda Staro-Bila was renamed into Starobelsk and became the administrative center of Starobelsk uyezd in Kharkov Governorate of the Russian Empire.

Founded on 12 October 1851, Starobilsk "Joy of All Who Sorrows" Convent (Свято-Скорботний жіночий монастир) became a spiritual center for the region. After the Bolshevik revolution, the convent was restricted and, in April 1924, it was closed down. In 1992, the state returned it to the Orthodox Church. It was reconsecrated and opened in 1995.