“Sometimes those who challenge us the most teach us the best,” said 20-time champion McCoy on Twitter.
“You did both to me for over 20 years. I will be forever grateful to you, thanks buddy. When you go home tonight look in the mirror you’ll see what a champion looks like. Enjoy your retirement.”
Johnson, who was in tears when McCoy retired in 2015, went on to be champion jockey himself four years running.
He won the Cheltenham Gold Cup for a second time in 2018 on Native River, 18 years after scoring with Looks Like Trouble.
Other major triumphs included the Queen Mother Champion Chase with Flagship Uberalles in 2002 and the Champion Hurdle on Rooster Booster a year later.
His brilliant last-gasp success in the 1999 Stayers’ Hurdle on Anzum was the first of his 23 winners at the Cheltenham Festival, and he was an awarded an OBE for services to racing in 2019.
Trainer Philip Hobbs, who saddled many of Johnson’s winners, said: “He’s been an amazing role model.
“You could not get anybody better for future jockeys to see what they need to do, how to conduct yourself and everything that is needed to be a good jockey.”
Fellow trainer Henry Daly said: “I can honestly say in 23 years we never had a crossed word – which is astonishing because I’m a grumpy git.”
Johnson’s final ride, Brother Tedd, was the horse he rode to victory in McCoy’s farewell race at Sandown six years ago.
Jockeys pay tribute to a racing great
Tom Scudamore: “Simply the finest bloke and friend you could wish to have. When I grow up I want to be like Richard Johnson.”
Aidan Coleman: “Richard Johnson has been my hero from when he spoke to me on my first ever ride, can’t find the words to describe what he means to me from both a personal and professional point of view.”
Harry Skelton: “Words wouldn’t be able to describe how good a person Richard Johnson is. He is the ultimate role model to any human in general life not just a jockey.”