Claims for the distinctiveness of third sector organisations are a relatively widespread and familiar feature of third sector commentary and analysis. This paper reviews relevant theoretical and empirical research to examine the idea of distinctiveness, arguing that such claims remain inconclusive. Informed by a view of the third sector as a contested 'field', and drawing on Bourdieu's notion of 'distinction', the paper suggests that research attention should focus additionally on the strategic purpose of claims for distinctiveness, rather than simply continue what might be a 'holy grail' search for its existence. The paper uses this argument to complicate and extend the idea of the third sector as a 'strategic unity', and concludes by suggesting some further lines of enquiry for third sector research.