Dawson said the nine-year-old bus cost $30,000. They have another bus but it isn't enough to transport the school's 650 pupils. Staff are scrambling to use their own cars to transport students while they're down to one bus.
Being based in a poor area means that transport is "out of reach" for some families, said Dawson. The school bus is free for all.
"We don't have to charge our kids any money to go out on the bus, we just manage the cost ourselves. We're a decile one school and that means a lot to us."
Hellen Seuula, 12, used the bus to get to her volleyball, soccer and netball practises. She called the bus "a treasure" to the school.
"To me the bus is full of memories. Usually we go and sing some songs, everyone gets together and has fun on the bus.
"We just want to tell that person to please bring back the bus. We really need that bus."
Seuula is in her last year at the school.
"I don't want to leave school without saying goodbye to the buses."
Dawson said the bus has Clendon Park School written all over it and should be easy to spot. While the bus is insured Dawson doesn't know if the payout will cover a new bus.
Police said they are investigating after the school bus was stolen from outside a residential address in Weymouth. At this stage the vehicle has not been recovered and there is no more information.
Police recommend to keep vehicles safe always ensure they are locked when unattended and parked in a secure location, preferably behind a locked gate overnight.