The popular British singer-songwriter known for the song "Imagine" is John Lennon. As a prominent member of The Beatles, he significantly influenced the music world through his revolutionary sound and groundbreaking lyrics. "Imagine," released in 1971, envisions a peaceful world without borders or divisions. Lennon's message of love and unity resonated widely, becoming an anthem for various social justice movements. His lasting impact transcends music, making him an enduring figure in the quest for global harmony and understanding.