Existing literature has not specifically examined individual business growth in post-growth economies. This paper challenges dominant assumptions in the business growth literature by considering post-growth economies as an organisational context characterised by natural resource scarcity and an absence of macro-level economic expansion. We investigate conceptually how such a context impacts business growth theory by seeking to answer three major questions: (1) What is business growth? (2) Why do businesses grow? (3) And how do businesses grow? Accordingly, post-growth contexts pose three major challenges to business growth theorising: (1) business growth as an increase in measurable outcomes, (2) resource competition and dispositive path dependencies, and (3) detrimental growth modes and strategies. Based upon six revised assumptions, we re-define business development in line with forces at work in post-growth economies. We further suggest a multidimensional research agenda that can catalyse future discussions of post-growth organisations. These discussions have the potential to overcome the inertia in business growth theory and its discrepancies with practice.