Abstract Diffuse gliomas are the commonest malignant primary brain tumour in adults. Herein, we present the most comprehensive analysis of the genomic landscape of adult glioma to date, by whole genome sequencing of 403 tumours. We identify an extended catalogue of recurrent coding and non-coding genetic mutations that represents a source for future studies and provides the most complete high-resolution map of structural variants, copy number changes and global genome features including telomere length, mutational signatures and genomic complexity. Finally, we relate these to clinical outcome. As well as identifying new DNA level drug targets for treatment of glioma findings offer the prospect of improving treatment allocation with targeted therapies.