The University of Glasgow, where Mr Kennedy studied and later served as rector, organised the memorial to pay tribute to its former student.
Scotland’s First Minister Nicola Sturgeon, Scottish Liberal Democrat leader Willie Rennie and Scottish Secretary David Mundell were among the congregation, along with former Lib Dem leader Menzies Campbell, Scottish Conservative leader Ruth Davidson and former Scottish Labour leaders Iain Gray and Johann Lamont.
Mr Kennedy’s partner, Carole MacDonald, also attended, along with former Labour spin doctor Alastair Campbell, a close friend of the former MP who lost his seat at the House of Commons in last month’s general election.
The father-of-one died suddenly earlier this month at the age of 55. He had suffered a major haemorrhage as a result of a long battle with alcoholism.
Mr Kennedy studied politics and philosophy at the university, graduating in 1982.
He also sharpened his renowned debating skills there, before being elected to Westminster the following year.
The politician received an honorary doctorate from the university in 2001 and was later elected rector in 2008, holding the position for six years.
He became the first Glasgow rector to be re-elected for a second term since former prime minister Benjamin Disraeli in the 1870s.
Tributes have poured in from all parts of the university community since Mr Kennedy died at his home in Fort William on 1 June.
Some 600 people filed into the University’s Bute Hall for the service, with broadcaster and journalist Muriel Gray among the congregation.
The service began with Mr Campbell and his brother, Donald, piping in leading figures from the university, the fourth oldest in the UK.
Sir Kenneth Calman, the Chancellor of the University, shared some of his memories of Mr Kennedy.
“We enjoyed each other’s company and there was always banter and humour between the serious parts of our conversation,” he recalled.
“The last time I was in touch with him was on18 April, returning from Culloden, where I had laid a wreath on the battlefield and realised I was driving through his constituency and I dropped him a note to wish him well.
“And I will always remember him with affection.”
He added: “In the 500th anniversary book of the university that was published in 1951, there was an inscription on the front page in Latin, Gaelic and English: ‘To the people of Scotland the heirs of our inheritance’.
“Charles contributed greatly to this university’s inheritance and to the people of Scotland.”
The service, led by university chaplain the Reverend Stuart MacQuarrie, included readings from Mr Mundell, Ms Sturgeon – who was also a student there – and Mr Rennie.
Lord Wallace, a former Scottish Lib Dem leader and former deputy first minister, told how he was elected on the same day as Mr Kennedy in 1983.
“We swiftly formed a close political friendship,” he recalled.
“It was a friendship which endured. I campaigned with him in the recent general election.”