Douglas Lloyd Ingle (born September 9, 1945) is an American musician, best known as the founder and former organist, primary composer, and lead vocalist for the band Iron Butterfly. Ingle wrote the band’s iconic song “In-A-Gadda-Da-Vida“, which was first released in 1968. He is the last surviving member of the classic 1967–1969 lineup.

Ingle had a short stint with the pop group Stark Naked and the Car Thieves in the early 1970s after he left Iron Butterfly.

Ingle was born in Omaha, Nebraska. His father Lloyd, a church organist, introduced him to music at an early age. Ingle moved from his native Nebraska within three months of his birth to the Rocky Mountains and later the family moved to San Diego.