A Mass will be celebrated at noon at St John's Roman Catholic Church in Caol, near his Fort William home.
The Mass will be led by Father Roddy McAuley, who has described Mr Kennedy as "a much loved and respected parishioner".
There is also to be a memorial service at the University of Glasgow on 18 June and another in London at a later date.
Mr Kennedy died suddenly a week ago at the age of 55 after suffering a major haemorrhage as a result of 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."
Mr Kennedy's body will be buried at Clunes, Achnacarry.
The family said: "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."
The funeral of former Lib Dem leader Charles Kennedy will take place on Friday, his family has said.