Since its nascency in the American pulp magazines of the 1920s, science fiction (SF) has had a particular relationship with the concept of seriousness. Characterised as juvenile in both its content and readership, SF has had to argue for its place in both literary and academic consideration. Debates about the strategies that could elevate the genre into serious consideration, or doom it to sneers, have been common since its birth, in both pulp magazine and literary journal. Despite SF having attained secure critical standing, these debates continue, with common talking points including the plausibility of the extrapolated science, the predictive power of authors, and the genre’s ability to estrange. However, the overarching concern of seriousness, and how it affects the interpretive process, has received little attention. This project aims to understand the different ways in which the concept of seriousness in SF proliferates through, and impacts on, the reading, writing and discussion of the genre. It understands seriousness as a negotiated concept, and therefore looks to SF’s discursive culture, as represented in discursive spaces such as magazines, fanzines, forums and reviews, to understand how the idea of 'serious SF' is differently created and used by different reading communities. It focuses its attention on three subgenres: two connected to movements which sought to make SF serious, New Wave and Cyberpunk; and one seen to embody ‘traditional’ SF stories, Space Opera.