Österreichischer Rundfunk (ORF [oːɛʁˈɛf] ^ⓘ; German pronunciation: [ˌøːstəʁaɪçɪʃɐ ˈʁʊntfʊŋk], lit. 'Austrian broadcasting') is the national public broadcaster and news website of Austria. Funded from a combination of television licence fee revenue and limited on-air advertising, ORF is the dominant player in the Austrian broadcast media. Austria was the last country in continental Europe after Albania to allow nationwide private television broadcasting, although commercial TV channels from neighbouring Germany have been present in Austria on pay-TV and via terrestrial overspill since the 1980s.

The first unregulated test transmissions in Austria began on 1 April 1923 by Radio Hekaphon, run by the radio pioneer and enthusiast Oskar Czeija [de] (1887–1958), who applied for a radio licence in 1921; first in his telephone factory in the Brigittenau district of Vienna, later in the nearby TGM technical college. On 2 September, it aired a first broadcast address by Austrian President Michael Hainisch (1858–1940). One year later, a powerful transmitter, designed by the German Telefunken company, was installed on the roof of the former War Ministry building in Ringstraße in central Vienna.

It was, however, the public Radio-Verkehrs-Aktiengesellschaft ('Radio Communication Company Ltd', RAVAG), a joint venture of the Austrian Federal Government, the City of Vienna and several bank companies, which, in February 1924, was awarded the concession to begin broadcasting, with Czeja as its director-general. Regular transmissions began on 1 October 1924 from provisional studios inside the War Ministry building that was to become known as Radio Wien (Welle 530). By the end of October 1924 it already had 30,000 listeners, and by January 1925 100,000. Relay transmitters, established across the country by 1934, ensured that all Austrians could listen to Radio Wien at a monthly fee of two schillings.

Radio programmes often aimed at an educated audience, featuring classical music, literature, and lectures. Early RAVAG shows, however, already catered to children and "arts and crafts" (e.g. Bastelstunde). The first outside broadcasts aired in 1925, transmitted from the Vienna State Opera and the Salzburg Festival. On the other hand, news broadcasts only played a minor part out of deference to the Austrian press and the 'neutralism' policy of the federal government (the July Revolt of 1927 was not even mentioned). Nevertheless, also regular sportscasts began in 1928 and in 1930 the Austrian legislative election was comprehensively covered. At that time, RAVAG registered about 500,000 listeners, having become a mass medium.

In the course of the abolition of the First Austrian Republic and the implementation of the Austrofascist Ständestaat by Chancellor Engelbert Dollfuß in 1934, the RAVAG studios were armed during the Austrian Civil War in February, as well as by the protagonists of the Nazi July Putsch, when several insurgents entered the studio and had Dollfuß's resignation announced (he actually was killed in his occupied Chancellery office). Dollfuß's successor Kurt Schuschnigg (1897–1977) had the demolished broadcasting centre replaced by the new Radiokulturhaus building (present-day Funkhaus Wien) near the Theresianum academy in Wieden, Vienna, designed by Clemens Holzmeister (1886–1983) and erected from 1935 to 1939. The Austrian government widely used RAVAG broadcasts for propaganda activities, defying massive cross-border Nazi propaganda broadcasts aired from German transmitters in the Munich region, but also promoted the live transmission of mass celebrations.

With the Austrian Anschluss to Nazi Germany and the invasion of Wehrmacht troops in 1938, RAVAG was dissolved and replaced by Reichssender Wien subordinate to the national Reichs-Rundfunk-Gesellschaft network (Großdeutscher Rundfunk from 1939) in Berlin, where programmes were also produced from. One of the last RAVAG transmissions was Schuschnigg's farewell address on 11 March 1938 ('God Save Austria'). Only hours later, live broadcasts featured the cheering devotees of his Nazi successor Arthur Seyss-Inquart (1892–1946), the triumphant entry of Adolf Hitler in Linz the next day, and his speech on Heldenplatz in Vienna. In 1939, the former RAVAG transmission facilities were taken over by the German Reichspost.

In World War II, listening to Feindsender ('enemy radio stations') became a capital offence, however, such stations such as the Swiss Radio Beromünster as well as the German-language programmes of the BBC, Voice of America (VOA) and Vatican Radio, were widely used information sources. Reichssender Wien transmissions were important for strategic bombing alerts. The Funkhaus broadcasting centre itself was damaged by Allied bombs in January and February 1945, followed by the Red Army Vienna Offensive. Reichssender Wien last aired 6 April, before retiring Schutzstaffel troops blew up the Bisamberg transmitter.

Following the Wehrmacht defeat, independent Austrian RAVAG radio broadcasting resumed in Allied-occupied Austria 24 April 1945, when it announced the formation of a provisional Austrian state government led by Karl Renner (1870–1950). A new Radio Wien station was founded, broadcasting from Funkhaus Wien by a provisional transmitter on the rooftop, once again under Oskar Czeija, who nevertheless was ousted shortly afterward on pressure by the Soviet military administration. As the Funkhaus was located in the Soviet occupation sector of Vienna, the Western Allies established their own radio stations like the Alpenland network on British-occupied territory, Radio Rot-Weiß-Rot on US-occupied territory, Sendegruppe West on French-occupied territory, as well as the American English-speaking 'Blue Danube' armed forces network (BDN; not to be confused with the later Blue Danube Radio) and the British Forces Network (BND), which became quite popular with younger Austrian listeners. The RAVAG/Radio Wien transmissions were limited to the Eastern Austrian Soviet occupation zone, and as the Cold War progressed was increasingly considered Communist propaganda broadcasting.