The Tandem Repeat Genome Aggregation Database (TR-gnomAD) is a biobank-scale reference of 0.86 million tandem repeats (TRs) derived from 338,963 whole-genome sequencing (WGS) samples of diverse ancestries, including 39.5% non-European samples. TR-gnomAD provides critical insights into ancestry-specific disease prevalence by analyzing disparities in TR unit number frequencies among ancestries. It also differentiates between common, presumably benign TR expansions and potentially pathogenic TR expansions. TR-gnomAD is an invaluable resource for interpreting TR expansions in genetic diseases. The study highlights the importance of TR expansions in human health and disease, with over 50 diseases linked to TR expansions. TR-gnomAD enables users to assess the prevalence or rarity of specific TR expansions within different ancestries and offers a tool for interpreting TR expansions in clinical settings. The database is freely available and includes a wide range of TRs, with future plans to incorporate more data from underrepresented populations. TR-gnomAD is a comprehensive resource for researchers, physicians, and genetic counselors to interpret TR expansions in individuals with genetic diseases.The Tandem Repeat Genome Aggregation Database (TR-gnomAD) is a biobank-scale reference of 0.86 million tandem repeats (TRs) derived from 338,963 whole-genome sequencing (WGS) samples of diverse ancestries, including 39.5% non-European samples. TR-gnomAD provides critical insights into ancestry-specific disease prevalence by analyzing disparities in TR unit number frequencies among ancestries. It also differentiates between common, presumably benign TR expansions and potentially pathogenic TR expansions. TR-gnomAD is an invaluable resource for interpreting TR expansions in genetic diseases. The study highlights the importance of TR expansions in human health and disease, with over 50 diseases linked to TR expansions. TR-gnomAD enables users to assess the prevalence or rarity of specific TR expansions within different ancestries and offers a tool for interpreting TR expansions in clinical settings. The database is freely available and includes a wide range of TRs, with future plans to incorporate more data from underrepresented populations. TR-gnomAD is a comprehensive resource for researchers, physicians, and genetic counselors to interpret TR expansions in individuals with genetic diseases.