The bombings came as Kyiv prepared to launch a counteroffensive to recapture Russian-occupied areas.
A residential apartment building in Uman was one of the structures hit, with a raging blaze killing 10 people, including two children, and injuring nine others.
In Dnipro, a missile struck a house and killed a woman and a two-year-old child, while three others were wounded.
The Ukrainian military claims to have taken down 21 of the 23 cruise missiles fired by Russia.
President Volodymyr Zelenskiy condemned the attacks and vowed to respond along with the international community.
The reason for Russia's attack is unknown, although it has previously targeted civilian infrastructure, especially energy facilities.
Although Moscow denies targeting civilians, it has killed thousands of people and destroyed towns and cities across Ukraine.
The capital Kyiv also witnessed explosions, with air defense units reporting that they had destroyed 11 missiles and two drones.
The war between Ukraine and Russia is escalating, with Kyiv set to launch a counteroffensive using hundreds of tanks and armored vehicles sent by Western countries.
The conflict centers on the eastern city of Bakhmut, where Russia seeks to gain control of the remaining parts of the Donbas area that it has yet to capture.
Russia holds territory across southeastern Ukraine and annexed the Crimea peninsula in 2014. (ILKHA)