In chaotic and emotional scenes, tens of thousands crowded the streets of Juba, capital of southern Sudan, as Garang's body was paraded slowly to the small Old Saints Cathedral.
Banners honouring Garang - who died in a helicopter crash last weekend, just three weeks after being sworn in as Sudan's first vice-president - fluttered throughout the town.
"Garang will remain alive through his vision, thoughts and principles," read one.
"Long live his struggle for the marginalised," said another.
Garang's death has stunned Africa, devastated his followers in the south of Sudan, triggered riots this week that left at least 130 dead, and fuelled fears that the January accord to end 21 years of southern rebellion may unravel.
After being flown around the vast southern region of bush and mountains so locals could pay homage, Garang's corpse was taken on Saturday from the town of Rumbek to Juba for formal burial.
Show of unity
In a show of unity, former fighters from Garang's rebel group, Sudan People's Liberation Movement/Army (SPLM/A), joined Sudanese army pallbearers to carry his coffin, draped in wreaths of pink, yellow and red flowers.
Garang's old enemy turned partner in the peace deal, Sudanese President Omar Hassan al-Bashir, stood in line to receive the coffin off a plane with South African President Thabo Mbeki and UN envoy Jan Pronk. A band played Auld Lang Syne.
"Garang will remain alive through his vision, thoughts and principles"
Banner honouring Garang
During the procession to church, women ululated and children held black flags aloft from bikes.
Armed SPLA fighters and Sudanese government security forces lined the streets.
The Ugandan presidential helicopter Garang was travelling in went down in bad weather in mountainous terrain and his supporters have said they do not suspect foul play.
Ugandan President Yoweri Museveni reiterated on Friday that the cause of the crash was unclear.
Calls for peace
Garang's death has raised fears that the January accord, which set up a power-sharing government and allowed southerners to vote on independence in six years, may collapse.
General Salva Kiir Mayardit will
replace Garang as vice-president
Arab League Secretary-General Amr Moussa, leaders from around Africa, and US and European officials also gathered in Juba for the funeral.
Just seven months ago, many of the same officials were in Nairobi for the 9 January signing of Sudan's deal to end the rebellion that killed two million people.
Both the rebels and the Sudanese government have called for calm.
Garang's successor, Salva Kiir Mayardit, has promised implementation of the peace accord, while Khartoum confirmed on Saturday that Kiir would be sworn in to replace Garang as first vice-president in the next two days.