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 and tissue-resident subsets. Despite well-defined epigenetic, transcriptional, and trafficking differences between these T cells, the phenotypic and functional delineation of circulating (TCIRCM) and resident-memory T cells (TRM), particularly across tissues, remain elusive. Here, we used InfinityFlow, a comprehensive screening platform of cell surface molecules combined with a machine learning prediction pipeline to investigate protein marker diversity between TCIRCM and TRM cells across multiple different tissues. This enabled high throughput screening of >250 surface molecules, that revealed four distinct TCIRCM populations with two main functional subtypes, and two broad TRM sub-populations across organs. Importantly, we elucidated differentially expressed cell surface proteins that permitted selective depletion of distinct T cell sub-populations, and we identified molecules that allowed for the stable demarcation of T cell subsets during inflammation and the characterization of their effector profiles. Together, our surface protein atlas provides a framework that allows the identification and functional classification of memory T cells at steady-state and in the context of disease.