BUB1 (Budding uninhibited by benzimidazoles 1), a mitotic checkpoint serine/threonine kinase, has been linked in numerous cancers to pro-tumorigenic phenomena including elevation of cellular proliferation, tumor growth, metastatic potential, and poorer patient prognosis. However, the role of BUB1 in glioblastoma remains poorly investigated. In this study, clinical analyses determined significant enrichment of BUB1 in glioblastoma with direct correlation of elevated expression to poorer prognosis in glioma patients. Genetic inhibition of BUB1 in glioblastoma tumor cells via shRNA silencing diminished both proliferative ability and tumorigenicity in vitro and in vivo. Silencing of BUB1 was additionally determined to promote the cytotoxic effect of irradiation on glioblastoma tumor cells, and investigation of the underlying pathways revealed the roles of DNA mismatch repair, spliceosome and c-Myc pathways. Mechanistically, FOXM1 was determined to positively regulate transcription of BUB1 via direct promoter region binding. For validation, pharmacologic inhibition through administration of a BUB1 inhibitor demonstrated attenuated glioblastoma cellular proliferation in vitro as well as delayed tumor growth with prolonged survival in vivo. Collectively, this study demonstrates a novel therapeutic target for glioblastoma in the form of BUB1, which plays a pivotal role in GBM proliferative and radio-resistance capacities in a FOXM1-dependant manner.