Ilovaisk (Ukrainian: Іловайськ, pronounced [iɫoˈwajsʲk] ; Russian: Иловайск) is a city in Donetsk Raion, Donetsk Oblast, Ukraine; residence of Ilovaisk urban hromada. The city is de facto under the military occupation of Russia and administered by the Donetsk People's Republic.

The city is known as a major regional railroad hub. It was also the site of a battle in the War in Donbas. The city has a population of 15,396 (2022 estimate), 17,620 (2001).

Starting in mid-April 2014, Russian paramilitaries captured several towns in Donetsk Oblast, including Ilovaisk. On 19 August 2014, Ukrainian forces reportedly secured the city centre from the Russia-backed militants; fighting for control of other parts of the town continued. The next morning they claimed they had control over one half of the town, with the town divided by a railroad line. On 21 August, the Ukrainian Armed Forces claimed that heavy fighting continued "in some districts of Ilovaisk", while the Russia-backed forces claimed they had repelled the Ukrainian military and surrounded a contingent of Ukrainian troops. Fighting for control of the town continued over the next days. The Russian Armed Forces retook the city as of 1 September 2014.

Ethnic composition according to the 2001 Ukrainian census.

Ethnic groups in Ilovaisk percent Ukrainians   56.76% Russians   40.15% Belarusians   0.69% Armenians   0.68% Greeks   0.28% Georgians   0.19% Azerbaijanis   0.17% Tatars   0.14% Moldovans   0.11%

Native language as of the Ukrainian Census of 2001:

Native languages in Ilovaisk percent Russian   82.6% Ukrainian   16.8% Armenian   0.2% Romani   0.1%

• Stanislav Hurenko (1936-2013), Ukrainian politician
• Mikhail Tolstykh (1980-2017), Ukrainian separatist and wanted war criminal

Media related to Ilovaisk at Wikimedia Commons