Sir Chris tackled the iconic sea stack off the north coast of Scotland to mark his 80th birthday.
He also hopes to raise awareness and funds for motor neurone disease (MND) charities in memory of his wife Wendy, who died of the condition last month.
Before setting off, Sir Chris admitted he was "apprehensive" about the climb.
He said: "I'm apprehensive having reached the age of 80 and having had all too little climbing in recent months because of my wife's illness."
Sir Chris was joined on the challenge by friend and fellow climber Leo Houlding.
Leo said before the start: "Weather's looking alright.  Sir Old Man on Hoy, here we go!"
The pair, who are both members of the Berghaus team of athletes, completed their ascent just before 17:00.
Matt Hickman, of Berghaus, tweeted: "Chris and Leo are on the top now!"
He had earlier said: "Chris is commenting that he isn't as flexible as the last time he did it!"
Sir Chris, who climbed Mount Everest in 1985, made the first ascent of the 449ft Old Man of Hoy in 1966.
He and colleague Tom Patey returned the following year and were part of the famous three-night live TV broadcast, The Great Climb.
The UK's most famous mountaineer Sir Chris Bonington has successfully climbed the Old Man of Hoy 48 years after his first ascent.