Dr. Demento is an American radio disc jockey specializing in novelty songs and pop music parodies.

Barret Hansen began his radio career in 1970 with an rock oldies show on KPPC-FM in Pasadena. He produced a segment featuring novelty music Steven Clean's show. who described Hasen as demented to play selections such as Transfusion by Nervous Norvus on the radio, and the persona was born. The Dr. Demento show ran on KPPC from January to October 1970 before moving to KMET where the four hour show aired live on Sunday's for 15 years. He continued live two-hour shows through 1997 on other stations inn the Los Angeles area with moves prompted by format changes first first to KLSX then to KSCA.

Hasen's weekly radio show was nationally syndicated from 1974 to 2010 first produced by Hansen's manager Larry Gordon, then by Westwood One Radio Prouctions through 1992, On the Radio Broadcasting from 1992-2000 under the name Talonian Productions then handling the national syndication himself until 2010. Syndicated programs were distributed national on vinyl LPs in the 1970s and 80s then CDs in the 90s and 2000s each with cue sheets.

Hansen also produced numerous compelation albums of demented music.