Onyeabor's songs are often heavily rhythmic and synthesized, occasionally epic in scope, with lyrics decrying war and sung by both Onyeabor himself and female backing vocalists. In the 2010s years a number of his songs have appeared on various compilations, most often his biggest hit, "Better Change Your Mind", which has appeared on Africa 100, World Psychedelic Classics 3: Love's a Real Thing - The Funky Fuzzy Sounds of West Africa, and Nigeria 70: The Definitive Story of 1970's Funky Lagos, through labels such as Luaka Bop.
Onyeabor was born into a poor family, but became financially successful enough to travel to Europe to study record manufacturing. Some biographies claim that he studied cinematography in Russia, returning to Nigeria in the 1970s to start his own Wilfilms music label and to set up a recording and production studio. He was later crowned a High Chief in Enugu, where he lived as a businessman working on government contracts and running his own semolina flour mill.  His business successes saw him named West African Industrialist of the Year in 1987. According to the Luaka Bop record label, Onyeabor "self-released eight albums between 1977 and 1985 and then became a born-again Christian, refusing to ever speak about himself or his music again." The label reports that through attempting to speak with Onyeabor himself, and by talking to people who seem to have firsthand knowledge, it has been trying to construct an accurate biography of him for the past 18 months, without success.
In 2014, the music website Noisey, affiliated to Vice magazine, released a 31-minute documentary entitled Fantastic Man that documents Onyeabor's history and legacy as well as Noisey's attempt to track him down for an interview. 2014 also saw a touring supergroup called the Atomic Bomb! Band come together to play Onyeabor's music at a series of concerts and festivals around the world. The group includes David Byrne (of Talking Heads), Money Mark (of the Beastie Boys), Damon Albarn (of Blur and Gorillaz), Dev Hynes (aka Blood Orange and Lightspeed Champion), Alexis Taylor (of Hot Chip), Charles Lloyd and Amadou and Mariam. Other admirers of Onyeabor's work include Dan Snaith, Four Tet and Tune-Yards.
In December 2014, William Onyeabor made his first radio appearance on the Lauren Laverne Show on BBC 6 Music, where he stated "I only create music that will help the world," whilst also admitting that he has never played live, and announcing that he had plans to release new material.
William Onyeabor died aged 70, peacefully, on January 16 2017, and leaves four children and four grandchildren.