Memory T cells are essential gatekeepers ensuring host protection against microbial and cancerous threats. Paradigmatically, memory CD8+ T cells can be broadly divided into circulating (TCIRCM) and tissue-resident memory T (TRM) cell populations based on their trafficking properties. Despite well-defined migratory and transcriptional differences between these T cell subsets, the phenotypic and functional delineation of TCIRCM and TRM cells, particularly across tissues, remains elusive. Here, we utilised a comprehensive screening platform of cell surface molecules combined with a machine learning prediction pipeline (InfinityFlow) to profile the expression of >250 protein markers in TCIRCM and TRM cells across multiple anatomical sites. High-dimensional analysis provided detailed phenotypic definition and revealed unappreciated heterogeneity within and between TCIRCM and TRM cell lineages in distinct tissue microenvironments. Importantly, we devised strategies that allowed for the selective ablation of distinct T cell subsets and identified stable markers allowing disentanglement of TCIRCM and TRM cells and the characterisation of their effector profiles during inflammation. Together, these data and analytical framework provide an in-depth resource to enable the identification, phenotypic interrogation, and functional classification of memory T cells at steady-state and in disease contexts.