Mediterranean. At 9.39 AM 6 miles West of the Greek island of Lefkada, British submarine HMS Thunderbolt attacks a convoy (German freighter Thessalia escorted by the Italian torpedo boats Solferino and Generale Carlo Montanari) with 3 torpedoes that all miss. Solferino drops 29 depth charges but HMS Thunderbolt escaped undamaged. At 2.10 PM, British submarine HMS Thorn sinks Italian submarine Medusa which is running on the surface near the Italian Naval base at Pola, Istria, in the far north of the Adriatic (57 killed, 1 survivor).

45 miles East of Grimsby, England, German bombers heavily damage British minesweeping trawler HMS Loch Alsh which sinks while under tow.

Operation Drumbeat. At 6.05 PM 100 miles East of Norfolk, Virginia, U-106 sinks American tanker SS Rochester (4 dead, 31 survivors rescued by US destroyer USS Roe).

Malaya. Allied troops complete the withdrawal according to plan, covering the last 20 miles to the Straits of Johore in trucks that outpace the Japanese pursuit. Overnight, British, Australians and Indians stream South across the causeway linking the mainland of Malaya to Singapore. Royal Navy runs small craft across the Straits of Johore to bring in stragglers. Overnight, British gunboats HMS Dragonfly and HMS Scorpion make a final run to evacuate the last British troops trapped at Rengit on the West coast.

Borneo. 400 Japanese troops (Land Drive Unit) leave Balikpapan in transport ships and land at Adang Bay 60 miles South along the coast. Their goal is then to cross 155 miles of jungle to reach Bandjermasin, the capital of Dutch Borneo. Sea Drive Unit left Balikpapan 3 days ago in small boats, traveling only at night to land on the coast 50 miles South of Bandjermasin. They too will trek inland through jungle to reach the capital.

Burma. Japanese 55th Infantry Division captures the airfield at Moulmein. Japanese bombers can now attack Rangoon, 100 miles West across the Gulf of Martaban.

62 miles Southeast of Madras, India, Japanese submarine I-64 sinks Indian freighter Jalatarang with torpedoes and the deck gun.

Overnight, 820 Japanese marines and 4000 Army troops land on Ambon (a small island in the Dutch East Indies 635 miles North of Darwin, Australia), supported by aircraft from carriers Hiry and Sry. Given the possible use of Ambon as an airbase to bomb Australia, the island is protected by 2800 Netherlands East Indies Army (KNIL) troops and Australian Army's 1,100-strong Gull Force, which arrived on 17 December. Due to the widespread landings at locations the Dutch had deemed untenable, Japanese make good progress inland and overrun small groups of defenders.