The Mass at St John's Church in Caol will be led by Fr Roddy McAuley who described the politician as "a much loved and respected parishioner".
He added: "He was a very humble and thoughtful person and he will be sorely missed. Our thoughts and prayers go out to all of his family. May he rest in peace."
Mr Kennedy, 55, died last week after a major haemorrhage caused by a long battle with alcoholism.
In a statement, his family said: "This will be an opportunity for Charles' family and friends, the local community he loved and served for so long, as well as his political friends to bid him a fond farewell.
"The police have informed us to expect large numbers of people and we will make arrangements for the service to be piped outside should the church be full to overflowing.
"We would like once again to thank the various authorities who have helped us through this difficult time.
"We have been touched by the care and sensitivity shown to us by the police, ambulance personnel, the office of the procurator fiscal, the registrar and Mike McFall, funeral director.
"We would also like to once again voice our heartfelt thanks to the public whose response has been so warm."
After his death the Lib Dem Christian Forum said it was "desperately sad".
Director Claire Mathys told Premier he was a man of faith: "He said he was a Catholic and he certainly did identify with the Christianity that has been a part of our British culture."
