Armed with briefcases full of cash, the Saudis handed out 100,000 rupiah (roughly $10) to every adult survivor and 50,000 to children in a relief camp.
"The situation here is bad. We want to help our brothers and sisters," one of the businessmen, Abd Allah Hamid, said on Saturday.
"We have a lot of money with us. We have already spent $2 million," he said.
Abd Allah said his group of business friends back in Saudi Arabia would also fund the construction of houses for the victims.
"My message to the people in Saudi and all over the world - do not forget these people. Help them," he said.
Entire communities on the western Aceh coast around Meulaboh were obliterated by the tsunami disaster, which left more than 160,000 people dead on Indonesia's Sumatra island.
Three weeks after the tsunami struck the south and southeastern Asian shoreline, the UN announced that more than $3 billion had been pledged in relief efforts.