• October 1 – Start of a statewide scrap drive. Nine men were killed when their B-17 bomber crashed east of Big Sandy.
• October 7 – A pilot was killed when his fighter plane crashed east of Stockett.
• October 9 – Antelope season ended after 657 antelope were harvested statewide.
• October 11 – Three Gore Field fliers were killed in a B-24 crash at Colorado Springs.
• October 13 – Italy declared war on Germany.
• October 14 – One passenger died, and 58 were injured when the Milwaukee Road Olympian train derailed near Miles City after the tracks washed out. Most of the victims were servicemen and WACs.
• October 16 – A fire in Billings caused $170,000 damage to the Stockman’s Bar, the Elks Club, and the Midland Bank Building.
• October 20 – Two dead, two injured in a Billings house fire.
• October 23 – A fighter pilot was killed in a crash near Lewistown. A hit-and-run driver killed a Billings woman.
• October 28 – Havre hosted 400 Farm Union delegates.
November 1943 (coming soon)