Tuberculosis (TB) is the leading infectious disease killer worldwide and children suffer disproportionately. The ongoing burden of disease, despite widespread vaccination with BCG, highlights the need for novel vaccines. MR1-restricted T (MR1T) cells are an innate-like T cell, defined by their recognition of bacterial and fungal metabolites presented by the monomorphic MHC class 1-related molecule (MR1). They have both “innate” effector capacity, allowing them to quickly respond to pathogens including Mycobacterium tuberculosis, and adaptive features (effector memory cell surface phenotype and selective TCR usage). Feasibility of MR1T cell-based vaccination remains unexplored and critical to this is whether MR1T cells possess the capacity for immunological memory. To begin to address this question, peripheral blood mononuclear cells (PBMC) were collected at 9-weeks of age from healthy term-infants in South Africa, who had either received BCG vaccination at birth (n=10) or who had BCG vaccination delayed (n=10). MR1/5-OP-RU tetramer positive cells were sorted using flow cytometry and single-cell RNA and TCR-seq were performed. Ex-vivo MR1T cells from vaccinated infants demonstrated increased expression of type I interferon response genes and a less diverse TCR repertoire suggesting selective expansion of TCR clonotypes in response to BCG vaccination. Using the previously published CoNGA algorithm, cells were clustered based on similarity in TCR and gene expression. Cells from BCG-vaccinated infants were enriched in a cluster that expressed increased pro-inflammatory and cytotoxic genes, potentially due to previous vaccination. Overall, these results suggest that a subset of MR1T cells are responsive to BCG vaccination and can be characterized by their response to type 1 interferons, a proinflammatory phenotype, and altered TCR usage. This work provides the first step in addressing if MR1T cells demonstrate immunological memory. However, further work is needed to understand if these clonal expansions persist and possess the capacity for antigenic recall.