The night-time attack on Odesa heavily damaged an apartment block, killing the women and a two-year-old child, officials said on Monday.
Rescuers working under floodlights pulled four people from the rubble.
Eleven people were hospitalised, including a pregnant woman and two children - the youngest less than a year old, Ukrainian President Volodymyr Zelenskiy said in a post on X.
Russia has pounded civilian areas of Ukraine since it invaded its neighbour just more than four years ago, killing more than 15,000 people, according to the United Nations.
It had also taken aim at Ukraine's power grid, and the Russian overnight barrages also hit energy infrastructure in the Chernihiv, Sumy, Kharkiv and Dnipro regions, Zelenskiy said.
More than 300,000 households were without electricity in the northern Chernihiv region after distribution facilities were damaged in attacks, according to the regional power utility.
In the past week, Russia has launched at Ukraine more than 2800 attack drones, nearly 1350 powerful glide bombs and more than 40 missiles of various types, according to Zelenskiy.
Zelenskiy expressed concern in a weekend interview with The Associated Press that the Iran war was draining stockpiles of weapons that Ukraine needed to defend itself, especially American-made Patriot air defence systems that can stop missiles.
Zelenskiy said on Monday the country's partners "need to strengthen air defence together so that the interception rate of drones and missiles continues to increase".
With US-led peace efforts stalled, Zelenskiy said: "Russia has no intention of stopping" its invasion.
Ukraine has fought back by developing its own long-range drones, which now reach targets some 1500km inside Russia.
Ukraine has used them recently to hammer Russian oil facilities as Moscow looks to boost its exports after the Trump administration gave it a temporary waiver from sanctions to ease supply constraints.
Kyiv officials complain that Russia will use the additional revenue on new weapons to hit Ukraine harder.
Russia's defence ministry said that air defences downed 50 Ukrainian drones overnight.
Krasnodar governor Veniamin Kondratyev said eight people, including two children, were injured in a series of Ukrainian drone attacks on Novorossiisk, one of Russia's largest Black Sea ports.
The attack damaged six apartment buildings and two private houses, he said.
Unconfirmed media reports said the drones targeted the Sheskharis oil terminal at the Black Sea port.
Last week, Ukraine's drones struck oil facilities in the Gulf of Finland, in northwest Russia.
