12 February – President of the United States Calvin Coolidge makes the first presidential political speech on radio. Broadcast from New York City, it is carried by five stations. It is listened to by an estimated five million people.
2 March – MIRAG, the Mitteldeutsche Rundfunk Aktien-Gesellschaft (Central German Broadcasting Co. Ltd), begins radio transmissions from Leipzig in Germany.
30 March – The Deutsche Stunde in Bayern GmbH (German Hour in Bavaria Ltd), begins radio transmissions from Munich in Germany.
1 April – SWR, the Südwestdeutsche Rundfunkdienst A.G (South-west German Broadcasting Service Ltd), begins radio transmissions from Frankfurt am Main in Germany.
2 May – NORAG, the Nordische Rundfunk Aktien-Gesellschaft (Northern Broadcasting Co. Ltd), begins radio transmissions from Hamburg in Germany.
12 May – SÜRAG, the Süddeutsche Rundfunk Aktien-Gesellschaft (South German Broadcasting Co. Ltd), begins radio transmissions from Stuttgart in Germany.
26 May – SFAG, the Schlesische Funkstunde Aktien-Gesellschaft (Silesian Radio Hour Ltd), begins radio transmissions from Breslau in Germany (modern-day Wrocław in Poland).
10 June – ORAG, the Ostmarken-Rundfunk Aktien-Gesellschaft (Eastern Marches Broadcasting Co. Ltd), begins radio transmissions from Königsberg in Germany (modern-day Kaliningrad in Russia).
2 August – The Deutsche Stunde in Bayern opens its second station, in Nuremberg.
15 September – Inauguration of Radio Agen in south-west France; the station is privately owned but supported by the département of Lot-et-Garonne.
6 October – URI begins regular broadcasting from station 1-RO in Rome.
10 October – WEFAG, the Westdeutsche Funkstunde Aktien-Gesellschaft (West German Radio Hour Ltd), begins radio transmissions from Münster in Germany.
14 November – Station EAJ-1 Radio Barcelona, the first radio station to receive an official licence from the Spanish government, begins regular broadcasting.
30 November – NORAG opens its second station, in Bremen.
1 October – RAVAG, the Radio-Verkehrs-Aktien-Gesellschaft (Radio Communication Co. Ltd) – a collaboration between government and private industry – is given responsibility for all radio broadcasting in Austria.
12 February – The Eveready Hour debuts on WEAF. It is considered the world's first commercially sponsored variety program.
20 December – First broadcast of the Norwegian children's radio programme Lørdagsbarnetimen ("Saturday children's hour") – on NRK radio, ending in 2010.