BRISBANE, Feb 14 - The student from Augusta State School quickly alerted her teacher on Tuesday, who zipped up the backpack's front pocket before a snake catcher took the venomous reptile away.
"I'm sure she would have had a shock," Snake Catchers Brisbane employee Lana Field said on Wednesday.
"Nobody has died from a red-bellied black snake bite in Australia, but their venom can lead to serious sickness."
Field said the snake was attracted to the dark colour of the young girl's Harry Potter Gryffindor backpack.
"Red-bellied black snakes love hiding in dark holes," she said.
Field said it was common to find snakes at schools and day care centres in southeast Queensland, but this was her first school bag discovery.
She explained the school, just on Brisbane's south-western fringes, has a creek and a rock wall creating a habitat that attracted snakes.
"We talk to the kids often so they know exactly what to do," she said.