The vehicle was taken from outside Rowan School on Durvale Court, in Dore, on either Friday, May 27 or Saturday, May 28.
It had been donated to the school by Lord's Taveners, Investec, Westfield Health and Friends of the Rowan School, and was described as a ‘vital’ resource for children there.
Headteacher Carla Ribeiro said: “The minibus provides the opportunity for all our children with special educational needs to access facilities in the local and wider community.
“These experiences are key to preparing children for adulthood and enable them to transfer the knowledge, skills and attitudes learnt in school to increase access to community opportunities.
“The bus is used daily to transport children to sporting events, swimming lessons, drama clubs and park visits.
“Minibus visits are a key feature of the school year, bringing learning to life and raise future aspirations for our children with SEND.
“The minibus is a vital resource that allows us to provide these opportunities for our children.
“If anyone has any information to help us find our bus please contact South Yorkshire Police.”
Rowan School, which was built in 1976, is rated ‘outstanding’ by Ofsted and has 97 pupils aged between four and 11.
South Yorkshire Police said in a statement that it was investigating the reported theft of the vehicle.
The force added: “Police have conducted enquiries to try and locate the vehicle, if anybody has any information please call 101 quoting crime number 14/98908/22.”