In stylistics, characterisation commonly refers to the cognitive process by which readers comprehend fictional characters. In effect, characterisation is the process of forming an impression of a character in your head as you read. This includes determining the personal qualities of the character in question as well as other aspects such as their social and physical characteristics. In this chapter I explain how stylistics has tackled the issue of characterisation. I begin by discussing four different views of the ontological status of characters. I argue in favour of the standpoint that sees characters as mental representations in readers’ heads. Consequently, I outline a particularly influential cognitive stylistic model of characterisation proposed by Culpeper (2001). I show how this can be used to uncover aspects of characterisation by analysing a number of extracts from prose and dramatic texts, as well as a longer extract from Dennis Potter’s 1978 TV drama Pennies from Heaven (D. Potter 1996). I focus particularly on the opening scene of the first episode. Finally, I demonstrate the practical value of understanding the characterisation process by analysing the hearing-impaired subtitles for the scene from the Pennies from Heaven DVD (Pennies from Heaven 1978). I show how the differences between these and the original dialogue are likely to impact on viewers’ impressions of the two characters in the scene.