Ono has consistently opposed parole for Mark David Chapman and has again sent a letter to the parole board, her lawyer, Peter Shukat, told the Daily News.
"Her position has not changed," Shukat said in an article published Tuesday.
Lennon was shot to death on December 8, 1980, outside the famed Dakota apartment building just west of Central Park as he and Ono returned home from a recording session.
Chapman -- now 55 and serving a 20-years-to-life sentence for the slaying -- is scheduled to be interviewed by a three-member parole board panel during the week of August 9. It will be his sixth bid for parole.
Shukat refused to say whether Ono's most recent letter to the board is the same one she has submitted every two years since Chapman first became eligible for parole in 2000.
In that letter, Ono wrote that if Chapman is released, "I am afraid it will bring back the nightmare, the chaos and confusion once again. Myself and John's two sons would not feel safe for the rest of our lives."
She also wrote that Chapman would not be safe if allowed back on the streets.
Due to his notoriety, Chapman is kept in a special unit apart from the upstate Attica prison's general population. He works as a porter, cleaning up offices, and assists inmates in one of the prison's law libraries.
Despite some early minor prison violations, Chapman's record has been clean since 1994, the Daily News said.
Robert Gangi, head of the prisoners' rights group, Correctional Association of America, doubts Chapman will be released because of the public outrage it would cause.
"Given that he committed a high-profile crime and he killed one of the most famous and most beloved figures literally in the world, it's highly unlikely three parole commissioners would vote to grant him release," Gangi told the News.
Lennon would have been 70 this October.