The band released its first single, "Love Me Do," in 1962 and, after enjoying worldwide popularity, broke up in 1968. Some Beatles fans have long held Ono responsible for the split.
"She certainly didn't break the group up," the BBC quoted McCartney, 70, as telling interviewer David Frost in a program to air next month on the al-Jazeera English TV channel.
"I don't think you can blame her for anything," McCartney said.
Lennon was "definitely going to leave" no matter what, he said.
The BBC reported McCartney also said Lennon, who was shot and killed in 1980, would not have written his classic song "Imagine" without Ono, an artist.
"When Yoko came along, part of her attraction was her avant garde side, her view of things," McCartney said. "She showed him another way to be, which was very attractive to him. So it was time for John to leave."