Lana Helen O'Connell, 23, sustained severe head injuries in the accident outside the Hi-So nightclub in Chalong district on Saturday, police captain Tienchai Duangsuwan said.
She was travelling with her boyfriend Ken Trivett, also 23 at the time.
"They bumped in to a pedestrian on the sidewalk and then he lost control and smashed into another motorcycle," Tienchai said in a telephone interview.
Her body was retrieved by relatives on Wednesday and flown home.
O'Connell was a swimsuit model and a student at Griffith University, according to Australian media reports.