The pensioner, who is Britain's most celebrated mountaineer, first scaled the 449ft island sea stack in 1966 as part of a team of three climbers.
Yesterday, he conquered the Orkney landmark for a third time, to raise funds for motor neurone disease (MND) charities in memory of his wife Wendy, who died of the condition last month, and to mark his 80th birthday.
Before setting off, Sir Chris 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."
However, updates were posted throughout the day yesterday on Twitter by outdoors clothing and equipment company Berghaus, where he is non-executive chairman.
Confirmation came through that Sir Chris had reached the top of the Old Man of Hoy, along with friend and fellow climber Leo Houlding, at about 5pm.
On Tuesday, he revealed that he was waiting for the weather to improve before beginning the ascent. In 1967 he had repeated his climb of a year earlier as part of a three-night live TV broadcast, called The Great Climb.
Sir Chris, who was knighted in 1996 for services to mountaineering, climbed to the peak of Mount Everest in 1985 at the age of 50 as a member of a Norwegian expedition. He started climbing at the age of 16 and has been on 19 Himalayan expeditions, including four to Everest. He has also worked as a writer, photographer and lecturer.
A spokeswoman for MND Scotland said: "We are delighted that Sir Chris Bonington is climbing the Old Man of Hoy to help raise awareness of Motor Neurone Disease, after the sad loss of his wife to the illness. Raising the profile of this rapidly progressing, terminal neurological illness is essential as many people still have little understanding of the disease."