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The baseline composition of T cells directly affects later response to pathogens, but the complexity of precursor states remains poorly defined. Here, we examined the baseline state of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–specific T cells in unexposed individuals. SARS-CoV-2–specific CD4⁺ T cells were identified in prepandemic blood samples by major histocompatibility complex (MHC) class II tetramer staining and enrichment. Our data revealed a substantial number of SARS-CoV-2–specific T cells that expressed memory phenotype markers. Integrated phenotypic analyses demonstrated diverse preexisting memory states that included cells with distinct polarization features and trafficking potential to barrier tissues. T cell clones generated from tetramer-labeled cells cross-reacted with antigens from commensal bacteria in the skin and gastrointestinal tract. Direct ex vivo tetramer …