The Transport and General Workers Union (TGWU) was created in 1922 from a merger of fourteen unions and continued to grow through a series of mergers, amalgamations and transfers of engagements. This process, which is recorded below in chronological order, continued through to 2007 when the TGWU itself merged with Amicus to form a new union called UNITE.

• Amalgamated Society of Watermen, Lightermen and Bargemen
• Amalgamated Carters, Lurrymen and Motormen's Union
• Amalgamated Association of Carters and Motormen
• Associated Horsemen's Union
• Dock, Wharf, Riverside and General Labourers' Union
• Labour Protection League
• National Amalgamated Labourers' Union
• National Union of Docks, Wharves and Shipping Staffs
• National Union of Ships' Clerks, Grain Weighers and Coalmeters
• National Union of Vehicle Workers
• National Amalgamated Coal Workers' Union
• North of England Trimmers' and Teemers Association
• North of Scotland Horse and Motormen's Association
• United Vehicle Workers

• National Union of Dock, Riverside and General Workers
• Scottish Union of Dock Labourers
• National Union of British Fishermen
• Greenock Sugar Porters' Association

• North Wales Craftsmen and General Workers' Union
• North Wales Quarrymen's Union

• Belfast Breadservers' Trade Union
• United Order of General Labourers

• Association of Coastwise Masters, Mates and Engineers
• Weaver Watermen's Association

• Irish Mental Hospital Workers' Union
• National Amalgamated Union of Enginemen, Firemen, Mechanics, Motormen and Electrical Workers

• Cumberland Enginemen, Boilermen and Electrical Workers' Union

• Public Works and Constructional Operatives' Union (Staffordshire District)
• Workers' Union

• Belfast Operative Bakers' Union
• Northern Ireland Textile Workers' Union

• Portadown Textile Workers' Union
• Scottish Farm Servants' Union
• London Co-operative Mutuality Club Collectors' Association

• National Union of Co-operative Insurance Society Employees
• Scottish Busmen's Union
• Altogether Builders' Labourers and Constructional Workers' Society

• National Winding and General Engineers' Society

• Electricity Supply Staff Association (Dublin)
• Halifax and District Carters' and Motormen's Association

• Power Loom Tenters' Trade Union of Ireland
• Belfast Journeymen Butchers' Association
• Scottish Seafishers' Union

• Humber Amalgamated Steam Trawlers' Engineers, and Firemen's Union
• Imperial War Graves Commission Staff Association
• Port of London Deal Porters' Union

• North of England Engineers' and Firemen's Amalgamation

• National Glass Workers' Trade Protection Association
• Radcliffe and District Enginemen and Boilermen's Provident Society
• National Glass Bottle Makers' Society

• Manchester Ship Canal Pilots' Association

• Grangemouth Pilots' Association

• Leith and Granston Pilots
• Dundee Pilots
• Methil Pilots

• Government Civil Employees' Association
• Liverpool and District Carters' and Motormen's Union

• Lurgan Hemmers' Veiners' and General Workers' Union

• United Cut Nail Makers of Great Britain Protection Society

• Scottish Textile Workers' Union

• National Union of Shale Miners and Oil Workers

• Gibraltar Confederation of Labour
• Gibraltar Apprentices and Ex-Apprentices Union
• Gibraltar Labour Trades Union

• North of Ireland Operative Butchers' and Allied Workers' Association
• United Fishermen's Union

• Cardiff, Penarth and Barry Coal Trimmers' Union

• National Association of Operative Plasterers
• Scottish Slaters, Tilers, Roofers and Cement Workers' Society

• Amalgamated Society of Foremen Lightermen of River Thames
• Irish Union of Hairdressers and Allied Workers
• Port of Liverpool Staff Association
• Process and General Workers' Union

• Sheffield Amalgamated Union of File Trades

• Scottish Commercial Motormen's Union
• Watermen, Lightermen, Tugmen and Bargemen's Union
• Chemical Workers' Union

• National Union of Vehicle Builders
• Scottish Transport and General Workers' Union (Docks)

• Iron, Steel and Wood Barge Builders and Helpers Association

• Union of Bookmakers Employees
• Union of Kodak Workers

• File Grinders' Society

• Grimsby Steam and Diesel Fishing Vessels Engineers' and Firemen's Union

• National Association of Youth Hostel Wardens
• Staff Association for Royal Automobile Club Employees

• National Union of Agricultural and Allied Workers
• National Amalgamated Stevedores' and Dockers' Society
• National Union of Dyers, Bleachers and Textile Workers

• Burnley, Nelson, Rossendale and District Textile Workers' Union
• Northern Textile and Allied Workers' Union
• Sheffield Sawmakers' Protection Society^[1]

• Amalgamated Union of Asphalt Workers^[2]
• National Tile, Faience and Mosaic Fixers' Society^[2]

• Lancashire Box, Packing Case and General Woodworkers' Society^[3]
• Yorkshire Association of Power Loom Overlookers^[2]

• Electrical and Plumbing Industries Union

• National Association of Licensed House Managers

• Northern Carpet Trades Union

• National Union of Lock and Metal Workers

• Community and Youth Workers' Union

In 2007 the T&G merged with Amicus to form Unite.

• List of trade unions