Due to Russian shelling of the Donetsk region, 4 people were killed and 7 were injured.
In Crimea, Russian troops began the engineering arrangement of defensive positions along the Krasnoperekopsk-Dzhankoy highway.

During the day, Russian occupiers shelled the Kherson region more than 70 times.
In Donetsk, Dmitry Rogozin was wounded as a result of shelling at a cafe. Two people nearby died.

Fierce fighting continues in the area of Bakhmut and Avdeevka in the Donetsk region and constant shelling of these settlements by the Russian army. Vladimir Zelensky visited the frontline Bakhmut.

The largest drone strike on Ukraine since the beginning of the war was carried out. Russia used 35 attack UAVs. Since the beginning of the war, Ukrainians have shot down 430 drones.

On December 18, an office of the regional branch of the Russian LDPR party was opened in Grozny. The ceremony was attended by party member Viktor Bout, who was released from an American prison and handed over to Russia as part of a prisoner exchange ten days earlier.

The Belgorod region of Russia was shelled. At least ten explosions were reported. One person died, several were injured.
In the Kharkov region, a hospital came under fire and one person was injured.

The Wall Street Journal, citing Ukrainian intelligence and security officials, reported that at the start of the full-scale invasion of Ukraine, Russian President Vladimir Putin ordered Chechen leader Ramzan Kadyrov to occupy government buildings in Kyiv and kill Ukrainian President Vladimir Zelensky.

On December 16, the chief prosecutor of the International Criminal Court (ICC) in The Hague, Karim Assad Ahmad Khan, announced the completion of the investigation into the August War, the 2008 Russian-Georgian armed conflict that took place in the territory of the self-proclaimed South Ossetia and Abkhazia.