- Oct 1 JB van Heutsz becomes governor general of Dutch East Indies
- Oct 1 Netherlands and Portugal lay down boundaries splitting the island of Timor in two
- Oct 2 German General Lothar von Trotha issues order to exterminate native Herero and Namaqua peoples of German South West Africa (present day Namibia); 1st genocide of the 20th Century, kills 65,000 Herero and 10,000 of the Namaqua tribe
- Oct 2 White Sox left-hander Doc White's streak of 45 consecutive MLB scoreless innings is snapped by the New York Highlanders in Chicago; White Sox win, 7-1 at South Side Park III
- Oct 3 France & Spain sign treaty for Morocco Independence
- Oct 3 Mary McLeod Bethune opens Daytona Normal & Industrial School
- Oct 3 New York Giants pitcher Christy Mathewson strikes out 16 Cardinals in a 3-1 Giants victory over St. Louis; new MLB record; finishes the game in 1 hour, 15 minutes
Chesbro's Season Record
Oct 7 NY Highlanders beat Boston Americans, 3-2 at Hilltop Park, NYC for pitcher Jack Chesbro's MLB record 41st win of the season (41-12)
- Oct 8 Vanderbilt Cup, first major trophy in American auto racing is conducted on public roads in Nassau County area of Long Island, NY; inaugural winner, American driver George Heath in a Panhard
- Oct 10 Boston pitchers achieve 148 complete games-an AL record, also record for total complete games AL 1,098, NL 1,089
- Oct 10 Liberty Theater opens at 234 W 42nd St NYC
- Oct 15 The Russians are driven back by the Japanese in the Battle of Shaho; both sides suffer high casualties: Japanese (16,000) and Russians (60,000)
- Oct 16 Russian Baltic fleet departs to Port Arthur
Bank of America Founded
Oct 17 Bank of Italy (Bank of America), founded by Amadeo Giannini, opens its doors in Jackson Square, San Francisco
Mahler's 5th Symphony
Oct 18 Gustav Mahler's 5th symphony premieres in Cologne, Germany
- Oct 19 Polytechnic University of the Philippines founded as Manila Business School through superintendence of American C.A. O'Reilley
- Oct 20 Bolivia and Chile sign a treaty ending the War of the Pacific; recognizing Chile's possession of the coast, providing for construction of a railway linking La Paz, Bolivia, to Arica on the coast
- Oct 22 Russian fleet shoots at British fishing ship
- Oct 27 First section of New York subway - Lower Manhattan to Broadway Harlem, opened by Interborough Rapid Transit (IRT), fare one nickel
- Oct 28 St Louis police try a new investigation method - fingerprints
- Oct 29 First intercity trucking service (Colorado City & Snyder, Texas)
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists