A Queensland woman is threatening legal action after her five-year-old daughter was left alone and trapped on a school bus.

Bobbie Langdon says her daughter Alyssa Jayde Langdon was "petrified and crying banging on the school bus doors to get out" when finally found about 7.30pm on Monday.

Bobbie Langdon posted this photo of Alyssa after the five-year-old's ordeal on the bus. Credit:Bobbie Langdon / Facebook

Ms Langdon had raised the alarm hours earlier, when she met the bus at the stop where her daughter was supposed to get off, but the five-year-old never did.

The year one student was seen at the front gate about 3.10pm, but police were told by Jimboomba State School and the bus company that Alyssa had not boarded the bus home.