Historians have frequently referred to the British Association for the Advancement of Science as an institution that had the professionalisation of British science as its chief aim. This article seeks to complicate this picture by asking what, if any, concept of "professionalisation" would have been understood by nineteenth-century actors. In particular, it seeks to move away from traditional functionalist understandings of professionalisation, as the possession of specialist knowledge and expertise, and consider instead broader definitions, which incorporate the power relationships and identities constructed through discourses of professionalisation. It argues that it was just as important for professional scientists in nineteenth-century Britain to possess a particular type of character (independent, rational, self-controlled) closely identified with popular ideals of elite masculinity and developed through a thorough scientific education. It also reinterprets the growing popularity of scientific internationalism, with its emphasis on the independence of the scientist (from state control) as a crucial part of this masculinising discourse of professionalisation.