| 1941 | January | 30 | 30: British forces in North Africa take Derna; 100 miles west of Tobruk. |
| 1942 | January | 30 | Hitler speaks at the Berlin Sportpalast and threatens the Jews of the world with annihilation; he also blames the failure of the offensive in Soviet Union on the weather. |
| 1943 | January | 30 | The last Japanese have cleared out of Guadalcanal by a brilliant evacuation plan undetected by the Americans. |
| 1944 | January | 30 | The Japanese kill 44 suspected spies in the Homfreyganj massacre. |
| 1944 | January | 30 | At Anzio, Italy the disastrous Battle of Cisterna took place, as MG John P. Lucas sent Darby's Rangers to begin the breakout from the beachhead. One of the four battalions in the action returned with only 6 of 767 men, the rest killed, wounded or captured. |
| 1944 | January | 30 | The Brazzaville Conference begins in French Equatorial Africa. During the conference (which lasts until 8 February), the French Committee of National Liberation (CFLN) agrees to major reforms to the French colonial empire. |
| 1944 | January | 30 | U.S. Navy shelling and carrier bombing began in the Marshall Islands, preliminary to invasions the following day. |
| 1945 | January | 30 | The Malta Conference (1945) began with Winston Churchill meeting with the Combined Chiefs of Staff on the Island of Malta in the Mediterranean to plan the end of WWII in both Theaters, and to discuss the ramifications of the Soviets now controlling most of Eastern Europe. President Franklin D. Roosevelt would join the Conference for one day on 2 February 1945; both would fly to Yalta on 3 February for the Yalta Conference with Stalin. |