• January 1 – Two new state supreme court justices were sworn into office.
• January 3 – U.S. Navy carrier aircraft bombed Formosa and the Ryukyu Islands.
• January 4 – Congress authorized $42 million for the construction of Hungry Horse dam.
• January 5 – Two Nisei working at Essex for the Great Northern Railroad were arrested in Kalispell for impersonating FBI agents.
• January 6 – A prisoner escaped from the Fort Missoula Detention camp.
• January 8 – Margaret Park in Great Falls was renamed Charles M. Russell Park.
• January 9 – The U.S. Army began landing at Lingayen Gulf on Luzon. A Gore Field pilot died in a crash in the Yukon.
• January 10 – Another Fort Missoula prisoner escaped.
• January 12 – A major Soviet offensive began on the Eastern front. Civilian ammunition sales halted once again.
• January 14 – Rep. James O’Connor died in Washington D.C. of a sudden heart attack at age 66.
• January 16 – Vandals broke 100 windows at Lowell School in Great Falls.
• January 18 – The Meatless Tuesday program was reinstated, as was butter rationing.
• January 20 – Rep. James O’Connor was buried in Livingston.
• January 21 – Hungary declared war on Germany.
• January 22 – Chinese forces cleared the Ledo road, opening a land route to China.
• January 25 – U.S. troops retook Clark Field in the Philippines. FBI agents arrested three Butte men suspected of operating a major auto-theft ring, and seized contraband tires, tubes and tools.
• January 30 – Fire destroyed the Eager Company store in Winnett, the largest business in Petroleum County.