With an estimated 400,000-700,000 deaths a year, neonatal sepsis is one of the leading causes of childhood mortality. Understanding neonatal immune cell development can inform strategies, such as vaccination, to combat neonatal sepsis. MR1-restricted T (MR1T) cells are an innate-like T cell, defined by their recognition of bacterial and fungal metabolites presented from the monomorphic MHC class 1-related molecule (MR1). In adults, the majority of MR1T cells express an invariant a-chain; TRAV1-2/TRAJ33/12/20, however, utilizing a MR1/5-OP-RU tetramer, we have previously shown that at birth neonatal MR1T cell demonstrate a much more diverse TCR usage and are predominantly TRAV1-2-. Understanding this diversity, along with the functional ability of TRAV1-2- MR1T cells, could provide insight into increased neonatal susceptibility to infections. To that end, blood mononuclear cells were collected from cord blood (n=5) and adults (n=5), sorted for MR1T cells utilizing a 5-OP-RU tetramer and single-cell RNA and TCR-seq (scRNA-seq and scTCR-seq) was performed. Cord blood-derived ex-vivo MR1T cells, demonstrated a less cytotoxic and less pro-inflammatory phenotype, as well as more diverse TCR expression. Next, MR1T cell clones were generated from both cord blood (n=1) and adult donors (n=1) by limiting dilution assay on sorted 5-OP-RU tetramer positive cells. scRNA-seq performed on PMA/Ionomycin-stimulated MR1T cell clones isolated from cord blood (n=3) and adults (n=3) showed that when stimulated, adult clones had increased expression of activation and pro-inflammatory genes compared to cord blood clones. Finally, clones were tested against a panel of common childhood pathogens, showing that cord blood MR1T cells recognized fewer microbes compared to adult MR1T cells. Overall, this data shows that cord blood MR1T cells, which express a diverse TCR repertoire, demonstrate a more restricted childhood pathogen recognition profile and diminished cytotoxic and pro-inflammatory capacity, as compared to adult MR1T cells.