Thirty years after the former Beatle died, the 77-year-old makes her surprising admission in the January issue of US Esquire.
She tells the magazine: “There is within me this feeling of guilt because I couldn’t stop it.”
Lennon was gunned down in New York City on 8 December 1980.
Obsessed fan Mark Chapman is still in prison for the singer’s murder, but Ono says she will not rule out conspiracy theories about who was behind her husband’s death.
Lennon’s widow doesn’t go into detail, but she says: “There are conspiracy theories. I’m not saying it was definitely just a deranged person.”
The Japanese artist opens up about her life lessons in the magazine’s monthly What I’ve Learned column, which has previously featured interviews with Ricky Gervais, Jodie Foster, Robert Redford and former US President George H W Bush, among others.
Speaking about Lennon’s death and her efforts to preserve his legacy, Ono says: “Obviously, it was a very negative thing for me to lose such a good partner. He was very good. He was a very strong and beautiful and protective force for me. But his words and his music are still here. It will still affect people…”
She adds: “I have a big job in addition to music: to keep his voice going… It was such a waste that he had to go when he was 40.”