The very Rev Dr Houston McKelvey will lead the Canons of St Anne's Cathedral on to Donegall Street for the annual event.
Dean McKelvey said, "It is probably going to be the toughest sit-out yet both economically and weather-wise."
The appeal raises money for various charities in Northern Ireland as well as Christian Aid.
This will be the last black santa sit-out for the Church of Ireland dean of Belfast, Rev Houston McKelvey, who announced he is to retire in April 2011.
Dean McKelvey said: "We will be in the street as usual each day from Thursday to Christmas Eve from nine in the morning to five in the evening.
"Relying as always on the tremendous generosity of the people, schools and businesses in our community.
Millions
"I extend an invitation to everyone to come and see us or 'our day off' on Sunday 19 December, when  we will present "Carols for the City" and celebrate the Christmas message of God's generosity.
"I would like to sincerely thank those who have already responded to our Postal appeal.
"It helps going on to the street knowing that £90,000 has already been given to this year's appeal."
Dean McKelvey plans to sit outside St Anne's Cathedral until Christmas Eve, continuing a tradition begun by his predecessors 30 years ago.
The charity vigil has raised millions since it began. Dean Sammy Crooks first started the collection in 1976.
Dean McKelvey first sat out for Christmas five years ago, following in the footsteps of his predecessor Dean Jack Shearer, who died in January 2001.
Dean Shearer was initially dubbed Black Santa by the media because of his distinctive clothing and the name caught on among the public.
The appeal raises money for various charities in Northern Ireland as well as Christian Aid.
Belfast's Black Santa is expected to begin his annual Christmas sit-out for charity on Thursday.