This study drew upon the theoretical frontiers of Systemic Functional Linguistics (SFL); the literary notion of characterisation; and the methodological locale of Corpus Linguistics (CL) to study the characterisation of Mathilde in the ideational metafunction of Maupassant's The Necklace. Drawing from Halliday's (1966) theorisation of SFL and DiYanni's (2002) conceptualisation of characterisation, the study has examined characterisation in a naturally occurring text titled The Necklace by use of a methodological backbone of CL methodology as espoused by Wu (2009). The corpus involved a single text hence the study was a monogeneric corpus-based study. Within the CL methodology, the ontological and epistemological dimensions of research were kept in check by the positivist and constructivist paradigms, thereby foregrounding a quantitative and qualitative approach to the study, respectively. Based on the nature of the objectives, a descriptive research design was used within which the qualitative and quantitative approaches were utilised. Content analysis was used as a method in analysing data obtained qualitatively while descriptive statistics was utilised in the analysis of data obtained quantitatively. Data collection and analysis drew on Wu (2009) and proceeded as follows: having read the story several times and understood it, the corpus was fed into the UAM Corpus Tool for semi-automated annotation. Frequency lists were then produced to categorise clauses into process-types. Thereafter, lexical and grammatical patterns associated with Mathilde were extracted. This was followed by the manual analysis of the data in accordance to Halliday (1971) in order to explore the characterisation of Mathilde. The findings have revealed that Mathilde is accorded material, mental, relational and verbal processes but denied behavioural and existential processes. The study further established that Mathilde is attributed transitivity patterns in process-types whose statistical distribution and placement in transitivity is deliberately chosen to characterise heras adesperate, materialistic, ungrateful, poor, fast-aging, lazy-turned-hardworking housewife, flamboyant and fantacist character.The study concludes that Mathilde is deliberately accorded some process-types whose statistical distribution characterises her in a different way from the other characters she appears with in the narrative.