Celebrations came as Kyiv awaits Moscow's official response to a 20-point peace framework prepared by Ukraine and the United States, which was presented by Ukrainian President Volodymyr Zelenskiy earlier this week following extensive negotiations with Washington.
In cities including Lviv, families, some joined by soldiers on leave or undergoing rehabilitation, walked through decorated streets in an effort to preserve a sense of the holiday.
However, the mood remained subdued as Russian strikes against energy infrastructure continued overnight and into Christmas Day.
Kharkiv, Ukraine's second-largest city, was among the hardest hit.
Authorities said the city's heating and electricity systems were damaged, killing one person and injuring at least 15 others as temperatures dropped to minus 11C.
"I'm not really feeling the Christmas spirit," said Kateryna Bushtruk, a 28-year-old artist from Zaporizhzhia, whose husband and father are fighting on the front line.
She said she does not expect to see them for several more months.
Bushtruk said she still decorated her apartment despite the circumstances.
"They want us to be afraid and miserable," she told EFE.
"That's why I do it."
In Lviv, hundreds of ribbons bearing the names of Ukrainian prisoners of war were placed beside a nativity scene.
Nearby, a Christmas tree stood at a site where families of captives regularly gather to urge international pressure on Russia to release detainees or improve their treatment.
"The celebration is only possible when everyone is at home," read one handwritten sign.
Another said: "This Christmas we wait for people, not miracles."
The return of all Ukrainian captives, both soldiers and civilians, is included in Zelenskiy's proposed peace framework, which also reflects Kyiv's willingness to discuss painful concessions, including de facto acceptance of Russia's occupation of roughly 20 per cent of Ukrainian territory.
Many Ukrainians, however, remain sceptical about Moscow's intentions.
"I dream that all our people will return home, but I don't believe the Russians will really give them back," Bushtruk said.
"They have already shown what their promises are worth."
While millions of Ukrainians shared Christmas Eve meals on Wednesday, many families were unable to do so.
Authorities estimate that around 50,000 residents from the western Lviv region are serving in the armed forces, with only a small number able to mark the holiday at the front, often with modest gatherings in dugouts.
In Lviv, families visited the city's military cemetery, where a "Mournful Carol" ceremony honoured hundreds of fallen soldiers.
Graves were decorated with Christmas trees and symbolic gifts, including toys and traditional sweets.
"There will be no peace until Russia sees our strength," said Olga Spodar, who spent Christmas at the grave of her 38-year-old son, Nazariy, a volunteer fighter killed a year after the invasion began.
She expressed doubt that negotiations would succeed.
"Russia will not stop attacking us," Spodar said.
"The only way to secure peace is for our soldiers to win and force Russia to leave us in peace."
Bushtruk echoed that view, saying Ukraine is paying an immense price.
"The best of the best are dying so that we can live, dream and build a strong, independent Ukraine," she said.
