Mykolaivka (, ; ) is a city and administrative centre of Mykolaivka urban hromada in Kramatorsk Raion, Donetsk Oblast, Ukraine to the south of the railway station Elektrychna. The city is most known for being the home of the Sloviansk Thermal Power Plant, where it is a major employer of local residents. The population estimate is about It is located in the historic region of Sloboda Ukraine.
On 4 July 2014, Ukrainian forces secured the city from pro-Russian separatists. The hospital began renovations in 2015, having been damaged in the fighting, with pro-Russian militants positioned around the building and on its roof. In 2016, the Verkhovna Rada appropriated the status of the city of district significance, withdrew it from the composition of the Sloviansk municipality and included it in the Sloviansk Raion.
On 28 September 2022, the city was shelled by Russia. One person is known to be killed.