Of all the influences on the early days of television, none were so direct and widespread as Golden Age {{radio}}.

The dawn of commercial radio began in 1920, with the first commercial stations, but little can be confirmed before 1926, since few authenticated recordings exist. It was in 1926 that Creator/{{NBC}} made its first broadcast, initially as the separate "Red" and "Blue" networks. Early broadcasts were primarily news or sports related, but ''The Happiness Boys'', a vaudeville duo, began a show in 1921 which continued until 1940. The "Golden Age" proper began around 1929. NBC was soon joined by Creator/{{CBS}}.

One noteworthy thing to happen during the Golden Age of radio was the episode of ''Radio/TheMercuryTheatreOnTheAir'' which aired on October 31, 1938. Director Orson Welles headed a production of Howard Koch's adaptation of ''Radio/TheWarOfTheWorlds''. It may say as much about the character of the time as the quality of the performance that many listeners actually believed the radio play to be a news report of an actual alien invasion. The resulting chaos is probably the reason that all subsequent US [[{{Mockumentary}} mockumentaries]] carry numerous disclaimers.

Many of the Golden Age radio dramas eventually [[SoundToScreenAdaptation made the move to television]], and several co-existed on TV and radio. But by the mid 1950s, televisions were becoming commonplace, and radio went into a decline. Most authorities agree that the "Golden Age" ended on September 30, 1962, with the final episodes of ''Radio/{{Suspense}}'' and ''Radio/YoursTrulyJohnnyDollar''.

Most Golden Age radio dramas suffer from some percentage of [[MissingEpisode missing episodes]], but, at least after the earliest days, these are surprisingly uncommon: Audio recording was cheap and the technology highly available, so recordings of 1930s and 1940s RadioDrama are available in much greater supply than their television contemporaries.

The advertising structure for Golden Age radio differed greatly from modern television. Shows typically had a single sponsor, which provided all the advertisement for the show. Actors would occasionally [[EnforcedPlug deliver in-character endorsements of the sponsor's product]]. As a result, an account could dry up, leaving the show commercial-free while the network "sustained" it. A perfect example of both items was again ''Radio/TheMercuryTheatreOnTheAir'' which ran for a period on the network's own expense until the "Radio/TheWarOfTheWorlds," made such a sensation that the Campbell's Soup Company jumped at the chance to sponsor the series, which led to it being renamed ''The Campbell Playhouse''. Economic forces being what they were, advertisements were almost always for consumable products (that is, automakers and long distance carriers need not apply), such as gum, wine and soap (which was mostly advertised during daytime dramas, leading to the term "SoapOpera"). One side effect is that almost all recordings of Golden Age radio drama available today still include the original commercials.

Another memorable feature of radio dramas was [[https://en.wikipedia.org/wiki/Radio_premium premium merchandising]], usually a tie-in to both the show and the sponsor's product. An entire plot thread could be built around use of the premium. One sent in three box tops and a dime, or the seal from under the Ovaltine lid, etc. ''ComicStrip/LittleOrphanAnnie'''s Ovaltine shake-up mugs and ''Franchise/CaptainMidnight'' Code-O-Graph badges are some of the best known.[[note]]While there were plenty of rings being offered, most "Secret Decoder Rings" were actually badges with cipher disks. An actual decoder ring ''was'' offered on ''WesternAnimation/JonnyQuest'' in the 1960s. [[/note]] Premiums weren't limited to kids; soap operas offered Helen Trent Friendship Necklaces and Ma Perkins Cookbooks.

It may also be worth noting that Golden Age radio shows tended to run much longer than television shows. The longest-running radio show was ''Radio/AmosAndAndy'', which began life in 1926 on NBC Blue under the title ''Sam and Henry''. It ran until 1960. The comparative ease and cheapness of production may have been a contributing factor (not to mention the fact that, lacking precedent, no one knew that 20 years was a long time for a show to run). However, since the audience didn't have to see the actors, it was easy and common to pull off a SisterBecky (''Radio/YoursTrulyJohnnyDollar'' went through ''six'' actors in the title role plus two more in audition episodes).

RadioDrama persists to this day, but only as a shadow of its former glory, mostly for nostalgia purposes. A brief revival in the 1970's led to shows such as ''Zero Hour'', ''General Mills Radio Adventure Theater'', a ''Radio/FantasticFour'' radio show, ''National Lampoon Radio Hour'' (which was a predecessor to ''Series/SaturdayNightLive''), the Creator/{{NPR}} production of ''Franchise/StarWars'', and the best known series of that era, ''Radio/CBSRadioMysteryTheater''.

Today, most radio dramas are one-off or miniseries events. One rare exception is ''Radio/APrairieHomeCompanion'', a long-running variety show hosted by Garrison Keillor.

In the United States, these are produced primarily by public radio affiliates. Creator/TheBBC also produces a number of these on the other side of the pond, the best known of which is the original incarnation of ''Radio/TheHitchhikersGuideToTheGalaxy''. Free from the financial constraints of commercial networks, Creator/TheBBC continues to broadcast regular dramas on two of its national networks (which have included adaptations of ''Literature/TheLordOfTheRings'', ''Literature/HisDarkMaterials'' and ''Literature/{{Discworld}}'' novels), and has also set up a digital channel, BBC7 (later BBC Radio 7; as of 2012 known as BBC Radio 4 Extra), as an outlet for archive radio drama and comedy. They also continue to broadcast one of the [[LongRunners longest-running]] {{Soap Opera}}s in the world, in the form of ''Radio/TheArchers'', which began as a thinly disguised farming advice broadcast, and has been running continuously 5 days per week since 1955. [=SiriusXM=] Radio has a channel dedicated to reruns of classic radio Dramas, mostly from 1948-1959.

For non-{{Radio}} audio dramas, see AudioPlay.

Most of the {{Formats}} and [[ShowGenres genres]], as well as many {{Tropes}} that are OlderThanTelevision, originated on radio, especially:

* TheCoconutEffect
* DramaticHalfHour
* NarratingTheObvious
* OpeningNarration
* TheOtherDarrin
* TheSummation
* VarietyShow

Notable and influential early radio series include:
* ''Creator/AbbottAndCostello'' (1940-1949)
* ''Adventure Time with ComicStrip/LittleOrphanAnnie'' (1931-1942)
* ''The Adventures of ComicStrip/JungleJim'' (1935-1954)
* ''Radio/TheAdventuresOfSuperman'' (1940-1951)
* ''Radio/TheAdventuresOfOzzieAndHarriet'' (1944-1954)
* ''Radio/TheAldrichFamily''
* ''Radio/AmosAndAndy'' (1928-1955)
* ''Radio/TheArchers'' (1951-[[LongRunners present]])
* ''Radio/BobAndRay''
* ''Radio/BoldVenture'' (1951-1952)
* ''ComicStrip/BuckRogers'' (1932-1947)
* ''Radio/TheBurnsAndAllenShow'' (1932-1950)
* ''Radio/TheCharlieMcCarthyShow'' (preceded by ''The Chase and Sanborn Hour'') (1937-1956)
* ''[[https://en.wikipedia.org/wiki/The_Cinnamon_Bear The Cinnamon Bear]]'' (1937)
* ''Radio/DimensionX'' (1950-1951)
* ''Radio/DrJekyllAndMrHyde'' (1932)
* ''Radio/{{Dragnet}}'' (1949-1957)
* ''Radio/{{Escape}}'' (1947-1954)
* ''Radio/FibberMcGeeAndMolly'' (1935-1956)
* ''Literature/FuManchu'' (1932-1933)
* ''Radio/{{Gangbusters}}'' (1935-1957)
* ''Radio/TheGreatGildersleeve'' (1941-1951)
* ''Franchise/TheGreenHornet'' (1936-1952)
* ''The Series/GuidingLight'' (1938-1956)
* ''Radio/{{Gunsmoke}}'' (1952-1961)
* ''Series/HaveGunWillTravel'' (1958-1960)
* ''Radio/InnerSanctum'' (1941-1952)
* ''Radio/TheJackBennyProgram'' (1932-1955)
* ''Radio/JourneyIntoSpace'' (1953-1958)
* ''Radio/LightsOut'' (1934-1947)
* ''Radio/TheLifeOfRiley'' (1941-1951)
* ''Radio/TheLivesOfHarryLime'' (1951-1952)
* ''Radio/TheLoneRanger'' (1933-1956)
* ''Radio/LumAndAbner'' (1931-1954)
* ''Radio/LuxRadioTheatre'' (1934-1955)
* ''Radio/TheMercuryTheatreOnTheAir'' (1938-1940)
** ''Radio/TheWarOfTheWorlds'' (Oct. 30, 1938)
* ''Radio/TheManBornToBeKing'' (1941-1942)
* ''Radio/MrDistrictAttorney'' (1939-1952)
* ''Radio/TheNewAdventuresOfSherlockHolmes'' (1939-1950)
* ''Radio/OurMissBrooks'' (1948-1957)
* ''Franchise/PerryMason'' (1943-1955)
* ''Radio/ThePhilHarrisAliceFayeShow'' (1948-1954)
* ''Radio/QuietPlease'' (1947-1949)
* ''Radio/RedRyder'' (1942-1949)
* ''Radio/TheShadow'' (1932-1955)
* ''Franchise/SherlockHolmes'' (1930-1956)
* ''Radio/TheStanFrebergShow'' (1957)
* ''Radio/{{Suspense}}'' (1942-1962)
* ''Radio/ThisIsYourFBI'' (1945-1952)
* ''Radio/TheWhistler'' (1942-1955)
* ''Radio/XMinusOne'' (1955-1958)
* ''Radio/YourHitParade'' (1935-1953)
* ''Radio/YoursTrulyJohnnyDollar'' (1949-1962)

Notable revival era shows include:
* ''Radio/TheAdventuresOfHarryNile'' (1976, then 1991-present)
* ''Radio/AlienWorlds'' (1978-1980)
* ''Radio/CBSRadioMysteryTheater'' (1974-1982)
* ''Radio/{{Earplay}}'' (???)
* ''Radio/FantasticFour'' (1975)
* ''Radio/GeneralMillsRadioAdventureTheater'' (1977)
* ''Radio/NationalLampoonRadioHour'' (1973-1974)
* ''Radio/SearsRadioTheater[=/=]Radio/MutualRadioTheater'' (1979-1980)
* ''Radio/StarWarsRadioDramas'' (broadcast in separate segments in 1981, 1983, and 1996)
* ''Radio/ZeroHour'' (1973-1974)
* The [[http://www.zbs.org/ ZBS Foundation]] (1970-present) is a non-profit arts organization that has specialized in creating a wide range of audio programs since its founding in 1970; and its broadcasts have been primarily on publically-funded radio stations. Currently, the organization focusses mainly on CD, downloadable, and podcast media; but still broadcasts on radio. Their longest and best known program is ''The Adventures of Ruby: Galactic Gumshoe'' -- first broadcast in 1982, with the most recent release in October, 2009. It's a spinoff of the Jack Flanders stories, which began with ''[[http://www.zbs.org/index_new.php/store/product/the-fourth-tower-of-inverness-original-radio-version-mp3 The Fourth Tower of Inverness]]'' -- a 1972 adventure remembered by elder tropers through a haze of pot smoke in the college dorm.

Notable British series that continued after the format died in the USA include:
* ''Radio/TheHitchhikersGuideToTheGalaxy'' (1978-1980, 2003-2005)
* In addition to the ''AudioPlay/BigFinishDoctorWho'' audio plays that have been going steady since 1999 one a month, there have been intermittent Doctor Who radio dramas from the mid eighties (with Colin Baker and Nicola Bryant), the nineties (with Jon Pertwee, Elisabeth Sladen and Nicholas Courtney) and the Aughts (Paul [=McGann=] as the Doctor and Sheridan Smith as a new companion).
* ''AudioPlay/BlakesSeven'' had two BBC Radio episodes starring the original cast, which was followed a decade later by a short reboot series. In 2011 Creator/BigFinish acquired the licence and began producing audio plays. (1998-1999, 2007-2011)
* ''AudioPlay/DoctorWhoAudioVisuals'' (1985-1991)
* Radio/RadioTheatre, from one of the creators of [[LongRunners long-running]] (1987-present) radio drama ''Radio/AdventuresInOdyssey'', does classic book series in dramatic format including Literature/TheChroniclesOfNarnia, the works of Creator/CharlesDickens, and Creator/GeorgeMacDonald. It is a joint American and British production. (1999-Present)
* ''Radio/TheScarifyers'' (2007-)
* ''Radio/CabinPressure'' (2008-2014)
* ''Radio/TorchwoodTheLostFiles'' (2011)
* A series of BBC 4 Radio plays based on the [[Literature/JamesBond James Bond novels]], starring Creator/TobyStephens as Bond: ''Dr. No'' (2008), ''Goldfinger'' (2010), ''From Russia With Love'' (2012), ''On Her Majesty's Secret Service'' (2014), ''Diamonds Are Forever'' (2015).

In Canada, Creator/{{CBC}} Radio One typically had one drama on its schedule until budget cuts killed the drama department.
Examples include:
* ''Radio/{{Afghanada}}'': Essentially Canada's ''TourOfDuty'' about Canadian soldiers serving in Afghanistan.
* ''Radio/{{Backbencher}}'': The misadventures of a rookie backbencher Member of Parliament serving in Canada's federal parliament in Ottawa.
* ''Radio/MonsoonHouse'': A series starring Russel Peters about the misadventures of an Indo-Canadian family and their small book publishing business.
* ''Radio/TrustInc'': The misadventures of a Toronto public relations firm.