- Oct 1 1st helicopter air mail & express service, LA, Ca
- Oct 1 The F-86 Sabre flies for the first time.
- Oct 1 US control of Haitian customs & governmental revenue ends
- Oct 1 William Wister Haines' "Command Decision" premieres in NYC
- Oct 2 Henry Duffy's musical "Music in My Heart", based on life and work of Piotr Tchaikovsky, opens at Adelphi Theater, NYC; runs for 124 performances
- Oct 2 New York Yankees catcher Yogi Berra hits the first pinch-hit home run in Baseball World Series history off Ralph Branca in the 7th inning of a 9-8 loss to the Brooklyn Dodgers in Game 3
- Oct 2 Revised International Telecommunication Convention adopted
- Oct 3 1st telescope lens 200" (508 cm) in diameter completed
- Oct 3 Manning Sherwin and Harold Purcell's musical "Under the Counter" opens at Shubert Theater, NYC; runs for 27 performances
- Oct 3 WMAL (now WJLA) TV channel 7 in Washington, D.C. (ABC) begins
Gionfriddo Robs DiMaggio
Oct 5 Brooklyn outfielder Al Gionfriddo makes famous catch off Joe DiMaggio in Game 6 of Baseball World Series; Dodgers beat Yankees, 8-6; catch inspires "back-back-back" expression
1st Televised White House Address
Oct 5 Harry Truman makes the 1st Presidential address televised from the White House
- Oct 6 Baseball World Series: NY Yankees beat Brooklyn Dodgers, 5-2 at Yankee Stadium to clinch series, 4 games to 3; 11th championship in team history
- Oct 7 Larry MacPhail resigns as NY Yankees GM after final game of 4-3 World Series win over Brooklyn Dodgers
- Oct 9 First telephone conversation between occupants of a moving car and an airplane
- Oct 9 Julie Styne and Sammy Cahn's musical "High Button Shoes" premieres at the New Century Theatre, NYC (later transferred to the Shubert, then to The Broadway Theatre, NYC; runs for 727 performances
Allegro
Oct 10 Richard Rodgers and Oscar Hammerstein's musical "Allegro" opens at Majestic Theater, NYC; runs for 318 performances
1st Supersonic Flight
Oct 14 Chuck Yeager in Bell XS-1 makes 1st supersonic flight (Mach 1.015)
Eisenhower Honored
Oct 14 Dutch Queen Wilhelmina gives golden award to general Eisenhower
- Oct 21 Dutch Dakota explodes near Copenhagen, 16 die
- Oct 21 J.B Priestley's stage drama "An Inspector Calls" opens at the Booth Theatre, NYC; runs for 95 performances
- Oct 23 Husband & wife Carl Cori & Gerty Cori are 1st spouses to be awarded joint Nobel Prizes for Physiology or Medicine for their discovery of the course of the catalytic conversion of glycogen" (alongside Bernardo Alberto Houssay)
- Oct 23 NAACP petition on racism "An Appeal to the World" presented to UN
- Oct 24 Series of forest fires burn over $30 million of timber across the New England States
- Oct 25 Bradman scores 156 for South Australia v India, 152 mins, 22 fours
- Oct 25 Manning Sherwin and Harold Purcell's musical "Under the Counter" closes at Shubert Theater, NYC, after 27 performances
- Oct 25 Sam Breadon sells Cards to Robert Hannegan & Fred Saigh for $4M
- Oct 26 Maharajah of Jammu & Kashmir accedes to India
- Oct 26 The British military occupation ends in Iraq
You Bet Your Life
Oct 27 "You Bet Your Life" with Groucho Marx premieres on ABC radio
Hymnus Ambrosianus
Oct 30 Darius Milhaud's 3rd Symphony "Hymnus Ambrosianus" premieres in Paris
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists