This article aims to provide a fresh approach to the study of hypercorrection, the misguided application of a real or imagined rule – typically in response to prescriptive pressure – in which the speaker's attempt to be ‘correct’ leads to an ‘incorrect’ result. Instead of more familiar sources of information on hypercorrection such as attitude elicitation studies and prescriptive commentary, insights are sought from quantitative and qualitative data extracted from the 2-billion-word Global Web-based English corpus (GloWbE; Davies 2013). Five categories are investigated: case-marked pronouns, -ly and non-ly adverbs, agreement with number-transparent nouns, (extended uses of) irrealis were, and ‘hyperforeign’ noun suffixation. The nature and extent of hypercorrection in these categories, across the twenty English varieties represented in GloWbE, are investigated and discussed. Findings include a tendency for hypercorrection to be more common in American than in British English, and more prevalent in the ‘Inner Circle’ (IC) than in the ‘Outer Circle’ (OC) varieties (particularly with established constructions which have been the target of institutionalised prescriptive commentary over a long period of time).