Officials said six drones struck a residential area just before dawn, injuring nine others.
The child, grandson of the local fire chief, died alongside his mother, police officer Daryna Shyhyda, and his grandmother.
Ukraine’s President Volodymyr Zelenskyy said the fire chief arrived to respond to the aftermath, only to discover his own home destroyed.
Separately, 17 were injured in Kharkiv, including children and a 93-year-old, while drone attacks also struck medical and educational sites in the Odessa region.