Charlie Bird and his supporters reached the summit of Croagh Patrick in Co Mayo on Saturday afternoon in an effort to raise funds for the Irish Motor Neurone Disease Association and suicide charity Pieta.
Tens of thousands of people took part in almost 200 Climb with Charlie fundraisers across the world, according to organisers.
The charity campaign, led by the broadcaster Mr Bird (72) who was diagnosed with motor neurone disease last year, has already raised more than €1.5 million.
@charliebird49 has reached the top of Croagh Patrick!! Go #climmbwithcharlie #mnd @IMNDA @PietaHouse pic.twitter.com/0bFlTQEvbw
— ClimbWithCharlie (@climb_charlie) April 2, 2022
Among those who took to the Reek on Saturday morning were Mr Bird's wife, Claire, daughters, Orla and Neasa, and five grandchildren, as well as singer Daniel O'Donnell, Matt Molloy of the Chieftains, boxer Barry McGuigan and the Late Late Show host Ryan Tubridy.
In a tweet on Saturday morning, President Michael D Higgins sent “every good wish and warmest support” to Mr Bird.
He said: "Charlie's strength and dignity over recent months has been a source of true inspiration to people across Ireland and beyond. I know that the public will be with him every step of the way."
Separate Climb with Charlie events were also planned across the world, in countries such as the United States, South Africa, Australia and Spain.
Other climbs included a 17.5km hike up Mount Cooke in Western Australia, a 700m-high climb up Ben Gorm in Co Mayo, a 6km night-time trek from Glenmore to Barnavave peak (350m) in Co Louth, and a 494m-high hike up Cnoc Bulaba.
The journey up Croagh Patrick began at 9.30am on Saturday from the mountain's base in Westport, Co Mayo.
Met Éireann forecaster Joanna Donnelly, who took part in Ireland, said it would be "mainly dry for the country" on Saturday with "scattered showers, though these should be mainly light".
Temperatures were expected to range between seven degrees in the east and about 10 degrees in the west “and as we climb of course it will be colder”.
Ahead of the climb Mr Bird, former RTÉ chief news correspondent, said he wanted Saturday to be a day of "joy and celebration".
“I have no idea how many people are going to scale the Reek with me, but I feel it is going to be a day like no other,” he added.
Mr Bird made a speech to his supporters and lit five candles in the church at the summit of the mountain; one for his friend Vicky Phelan, one for people suffering a terminal illness, one for anyone in a dark place with their mental health, one for everyone involved in the fight against Covid and one for the people of Ukraine.
The Climb with Charlie campaign is still accepting donations on www.climbwithcharlie.ie for the Irish Motor Neurone Disease Association and Pieta.