Radio broadcasting began in New Zealand in 1922, and is now dominated by almost thirty radio networks and station groups. The Government has dominated broadcasting since 1925, but through privatisation and deregulation (in 1989) has allowed commercial talk and music stations to reach large audiences. New Zealand also has several radio stations serving Māori tribes, Pasifika communities, ethnic minorities, evangelical Christians and special interests.

State-owned broadcaster Radio New Zealand reaches the broadest range of listeners with bilingual flagship broadcaster Radio New Zealand National. Several previously state-owned radio brands like top-rating talk station Newstalk ZB are now owned by NZME Radio, which operates eight networks on terrestrial radio and iHeartRadio. Ten radio networks are operated by MediaWorks New Zealand, including top-rating music stations The Edge and The Rock. Independent stations like The SkiFM Network, 1XX and Coast FM continue to serve local communities, alongside low-powered and internet stations.

New Zealand was also one of the first countries to introduce Christian radio, with Rhema Media now operating three networks around the country. The Student Radio Network began with the start of bFM in 1969 and the first of the country's community access broadcasters was founded in 1981. Te Māngai Pāho funds Māori iwi radio stations, and the Pacific Media Network continues to receive Government support.

Professor Robert Jack made the first broadcast in New Zealand from the University of Otago physics department on 17 November 1921. The first radio station, Radio Dunedin, began broadcasting on 4 October 1922, but it was only in 1925 that the Radio Broadcasting Company (RBC) began broadcasts throughout New Zealand.

Auckland Radio Service started broadcasting at 7:45pm on 13 April 1923 and 1YA was soon being heard on 4 evenings a week as far away as Dunedin. The government facilitated the creation of RBC and gave it a 5-year contract. Auckland Radio was then taken over by the Radio Broadcasting Company of New Zealand on 20 November 1925. A new studio, with a more powerful transmitter and 204 ft (62 m) mast, opened on 9 August 1926 in Newton and could be heard in Rarotonga. It cost about £8,500 and used a 500W International Western Electric Company transmitter, able to reach most of the country. RBC's similar 3YA in Christchurch started broadcasting on 1 September 1926. Its 2YA Wellington studio was officially opened on 16 July 1927. Listenership rose rapidly, from 3,588 licences in 1926 to 18,162 in 1927.

In addition to those stations, in 1923 there were also Auckland stations 1AA (C.N. Edwards), 1AB (V.J. Penny), 1AC (L.S. Spackman), 1AH (Hartle & Gray), 1AM (Hamilton Amateur Radio Club), 2YA (then owned by Wilkins & Field, Nelson), 2AB (D. Wilkinson, Motueka), Gisborne had 2AD (P.R. Stevens), 2AE (R.J. Patty), 2AF (W.J. Sinclair), 2AG (I.H. O'Meara), a 2AG station (L.K. Ewen) was also in Whanganui, as was 2AH (Whanganui Amateur Wireless Club), 2AI in Wellington (W.L. Harrison), 2AJ in Stratford (Bransgrove), 2AK (L. Rawson, Hāwera), 2AP (P. Collier, Brooklyn) 2YK (Dominion Radio, Wellington), 2XA (Experimental Station, Wellington), Christchurch stations 3AA (R.J. Orbell), 3AB (F. Vincent), 3AC (Radio Society), 3AF (L.F. Ball), Greymouth 3AD (R.G.F. Blake), 4AA (F.D. Bell, Palmerston), 4AC (R.E. Robinson, Dunedin), 4AD (A.E. Jordan, Invercargill), 4YA was then owned by British Electric Supply and, with 4YO (Radio Supply Company), also in Dunedin, and 1YA (then Auckland Radio Service) had the only three 500 watt transmitters in the country. Further stations in 1926 were 1YC (N.C. Shepherd, Whangārei), 1YD (L.R. Keith, Auckland) and 2YL (B. C. Spackman, Napier).

In 1930, station 1ZR began operating from the Queen Street premises of Lewis Eady Limited in Auckland. Pioneer broadcasters included Aunt Daisy, Dudley Wrathall and Rod Talbot. A "radio church", the 'Friendly Road', was run by 'Uncle Tom' Garland and the Reverend Colin Scrimgeour.

In 1932, RBC's assets were acquired by the government, which established the New Zealand Broadcasting Board (NZBB). This would later be replaced by the New Zealand National Broadcasting Service (NBS) and the National Commercial Broadcasting Service (NCBS). In the 1950s, these merged to become the New Zealand Broadcasting Service (NZBS), a government department. In 1962, this gave way to the New Zealand Broadcasting Corporation (NZBC), an independent public body modelled on the BBC in the UK.