Barret Eugene "Barry" Hansen (born April 2, 1941), better known as Dr. Demento, is an American radio broadcaster and record collector specializing in novelty songs, comedy, and strange or unusual recordings dating from the early days of phonograph records to the present.

Hansen created the Demento persona in 1970 while working at Los Angeles station KPPC-FM. After Hansen played "Transfusion" by Nervous Norvus on the radio, DJ "The Obscene" Steven Clean said that Hansen had to be "demented" to play that. Thereafter, the name stuck. His weekly show went into syndication in 1974 and from 1978 to 1992 was syndicated by the Westwood One Radio Network. Broadcast syndication of the show ended on June 6, 2010, but the show continues to be produced weekly in an online version.