Mourners gathered on the tarmac at Sydney Airport to see off Captain Ian H. McBeth, 44, of Great Falls, Montana, and First Officer Paul Clyde Hudson, 42, of Buckeye, Arizona, as their flag-draped caskets were lifted into aircraft for the journey home.
Fire trucks were parked nearby with their emergency lights flashing.
The men and a third American, flight engineer Rick A. DeMorgan Jr, 43, of Navarre, Florida, were killed in a plane crash in remote bushland while battling fires on Jan. 23, in one of the deadliest days of Australia's most destructive bushfire season in a generation.
The three were among hundreds of North American firefighters who joined an international effort to tackle the fires that have killed eight firefighters and 33 people in total.
As searing temperatures and strong winds subsided, and weather forecasters predicted several days of rain, Australia has turned its attention to the emotional toll after months of near-constant emergency warnings and toxic smoke across the southeast.
Prime Minister Scott Morrison suspended the first day of parliament after the summer break on Tuesday to lead a tribute to fire victims.
On Wednesday, senior U.S. embassy officials along with top Australian fire and emergency service officers stood at attention alongside relatives of the men as hearses slowly crossed the tarmac to the planes which would carry them home.
Representatives of Coulson Aviation, the private Canadian company that employed the trio and owned the C-130 tanker which crashed, were at the ceremonies.
The Australian Transport Safety Bureau is investigating the crash which occurred after the air tanker dumped retardant on a huge wildfire in mountains in a national park south of Canberra, the capital.The third man killed in the crash, DeMorgan, would be honored at a ceremony at a military base north of Sydney on Saturday before his remains were returned home.