- Sep 5 Jack Coombs begins a record streak of 53 shutout innings
- Sep 6 Saskatchewan (then Regina) Roughrider football club formed
- Sep 7 In the Hague, the International Court arbitrates a fishing-rights dispute between the US and Newfoundland (still separate from Canada)
- Sep 10 Great Idaho Fire destroys 3 million acres of timber
- Sep 11 1st commercially successful electric bus line opens (Hollywood)
- Sep 12 Gustav Mahler's 8th Symphony premieres in Munich with 1028 musicians
- Sep 12 United States' 1st known female cop appointed, Alice Stebbins Wells by LAPD
- Sep 13 Regina Rugby Club forms
- Sep 15 Boers & Afrikaners win 1st general elections in Union of South-Africa
- Sep 18 25,000 demonstrate in Amsterdam for general male/female suffrage
- Sep 19 George Cohan's "Get-Rich-Quick Wallingford" premieres in NYC
- Sep 22 Saskatchewan Rugby Football Union forms
- Sep 22 The Duke of York's Cinema opened in Brighton. It is still operating today, making it the oldest continually operating cinema in Britain
- Sep 27 1st test flight of a twin-engined airplane (France)