Mr Kennedy, who led his party from 1999 to 2006, lost his seat last month. No cause of death has been given but police said it was not suspicious.
Charles Kennedy was a democratic leader. He left a mark on British politics. The man who took his party to its electoral peak, he was the only UK party leader to warn the country of the perils of invading Iraq when Labor and the Conservatives were uniting to support it.
Mr Clegg, who will step down as Lib Dem leader next month, said that on a good day Mr Kennedy had “more political talent in his little finger than the rest of us put together”.
“Charles devoted his life to public service, yet he had an unusual gift for speaking about politics with humor and humility which touched people well beyond the world of politics,” he said: “He was one of the most gentle and unflappable politicians I have ever known, yet he was immensely courageous too not least when he spoke for the country against the invasion of Iraq.”
Mr Kennedy’s political career began in the Social Democratic Party and he became the youngest MP of the time at the age of 23 when he won the Ross, Cromarty and Skye seat in 1983.
At first he was S.D.P spokesman on social security, Scotland and health and when most of his party merged with the Liberals to form the Lib Dems in 1988, he continued to hold a series of frontbench posts. He took over the Liberal Democrat leadership from Paddy Ash-down in 1999.
His 2002 marriage to Camelot public relations executive Sarah Gurling was seen by many in the party as a sign he was settling down. The birth of his son in 2005 was seen as a further sign that the hard-partying Kennedy – one commentator had dubbed him “Jock the lad” – was being transformed into a family man, although he and his wife split up in 2010.
“Charles’s death is an absolute tragedy. He was throughout his time a lovely, genuine and deeply committed public servant,” he said: “As leader of the Liberal Democrats, we worked closely together, and he was always great company, with a lively and inventive mind.”