January 1 – All major railways in Great Britain are amalgamated into the "Big Four" companies, the Great Western Railway, London and North Eastern Railway, London, Midland and Scottish Railway and Southern Railway, under terms of Railways Act 1921.
January 30 – The Canadian National Railway (CN) absorbs the Grand Trunk Railway and spins off the portion of the Grand Trunk within the United States to form the Grand Trunk Western Railroad (GTW); CN operates GTW as a subsidiary railroad. National ownership encourages freight rates favoring use of Canadian seaports in the Maritimes, and causes declining freight volumes over the New England line to Grand Trunk seaport facilities in Portland, Maine.
February 7 – London and North Eastern Railway (Great Britain) takes delivery of express passenger 4-6-2 steam locomotive Flying Scotsman from its Doncaster Works.
March 10 – Norfolk and Western Railroad (United States) takes delivery of its first Y3a Class 2-8-8-2 steam locomotive from ALCO.
April 1 – Yamaguchi Line, Ogori (Shin-Yamaguchi) to Masuda route officially completed in Japan, a direct passenger express service start from October 1961.
July 6 – Ongarue railway disaster: In New Zealand, about 6:00 am, the southbound Auckland to Wellington express rounds a sharp bend and ploughs into a landslip which had fallen across the railway line near Ongarue, just north of Taumarunui. 17 passengers die and 28 others are injured.
July 11 – The Ofoten Line in Norway takes electric traction into use.
July 15 – Warren G. Harding, President of the United States, drives the golden spike on the Alaska Railroad.
July 18 – In the United States, Fruit Growers Express (FGE) and the Great Northern Railway form the Western Fruit Express (WFE) in order to compete with the Pacific Fruit Express and Santa Fe Refrigerator Despatch in the west.
July 20 – First Victorian Railways electric locomotive, #1100 built at its Newport Workshops, is placed into freight service in Melbourne, Australia.
August 1 – City of Glasgow (Scotland) takes over operation of the Glasgow Subway.
August 4 – The Otira Tunnel (8.5 km) on the Midland Line in New Zealand opens, worked by electric traction; construction had started in 1907 and at opening it is the longest in the British Empire (and remains the longest in South Island).
August – Great Western Railway (Great Britain) takes delivery of its first 'Castle' Class 4-6-0 express passenger steam locomotive from its Swindon Works, No. 4073 Caerphilly Castle.
September 27 – Following soon after the washout of Chicago, Burlington and Quincy Railroad's bridge over Coal Creek (near Glenrock, Wyoming), a passenger train falls through the washout, killing 30 of the train's 66 passengers. The accident is the worst railroad accident in Wyoming's history.
U.S. Interstate Commerce Commission allows Southern Pacific Railroad's control of the Central Pacific Railroad to continue, ruling that it is in the public's interest.
Munising, Marquette and Southeastern Railway and Lake Superior and Ishpeming Railway merge to form the Lake Superior and Ishpeming Railroad.
The Gold Coast Government Railway's Accra–Kumasi direct line is completed.
Robert R. Dowty, construction foreman for the Jupiter and 119 steam locomotive replicas at the Golden Spike National Historic Site at Promontory, Utah (died 2004).
Margaret Landry Moore, "Miss Southern Belle" spokesmodel for Kansas City Southern's Southern Belle passenger trains (died 2005).
Frank Turpin, CEO of Alaska Railroad, 1985–1993 (died 2005).
April 10 – Stuyvesant Fish, president of Illinois Central Railroad 1887–1907 (born 1851).
May 16 – George Jay Gould I, eldest son of Jay Gould, president of the Denver and Rio Grande Western Railroad and the Western Pacific Railroad (born 1864).
October 25 – Henry Ivatt, Chief Mechanical Engineer of Great Northern Railway of England 1896–1911 (born 1851).
December 5 – Sir William Mackenzie, part owner of Toronto Street Railway, builder of Canadian Northern Railway predecessors (born 1849).
December 10 – Thomas George Shaughnessy, president of Canadian Pacific Railway Limited 1899–1918 (born 1853).
1923 in rail transport Wikipedia
This article lists events related to rail transport that occurred in 1923.