This paper develops the building blocks for analysing persona across cultures. Comparative persona is an emerging area of both analysis and investigation. It recognises that there are patterns across cultures in the display of the public self; but of equal importance there are differences in these nation-specific public personas and the cultural systems and traditions actually lead to different and particular arrays of public individuals. This paper works on developing a lexicon and terminology to help describe the intrinsic and extrinsic dimensions of persona in national settings. From an analysis derived from close studies of the systems of celebrity in national cultures, the paper starts a parallel investigation as to whether these same public persona patterns are evident in the way that the wider populace produce their own mediatized public personas in online culture via social network sites. It proposes a future large-scale international project to explore these two levels of persona construction: first via a study of national celebrity systems and then by a study of persona in online culture.