The MIrreM Public Database on Irregular Migration Stock Estimates (the Database) provides an inventory and critical appraisal of country-level estimates of irregular migration stocks in 13 European countries, the United States and Canada for the period 2008 to 2023. It is a deliverable of the MIrreM project, which is a follow-up to Clandestino. Clandestino covered the period 2000-2008. Users of the Database are advised to consult the following companion documents: The README File (version 3), which can be accessed alongside the Database, and contains contextual and technical information about the Database. Discussion of the context, the underlying concepts, and the methodology used in the data collection and quality assessment: Vargas-Silva, C., Leerkes A., Kierans, D., Siruno, L. and Kraler, A. (2025). Tools for collecting information on irregular migration estimates and indicators. Open Research Europe 5:176. https://doi.org/10.12688/openreseurope.20695.1 Analysis of the stock estimates: Kierans, D. and Vargas-Silva, C. (2024). The Irregular Migrant Population of Europe. MIrreM Working Paper No. 11. Krems: University for Continuing Education Krems (Danube University Krems). https://doi.org/10.5281/zenodo.13857073 Furthermore, users of the Database are notified of a ‘sister’ database of the MIrreM project, which captures and assesses estimates and indicators of irregular migration flows over the same period, the MIrreM Public Database on Irregular Migration Flow Estimates and Indicators and accompanying analysis: Siruno, L., Leerkes, A., Badre, A., Bircan, T., Brunovská, E., Cacciapaglia, M., Carvalho, J., Cassain, L., Cyrus, N., Desmond, A., Fihel, A., Finotelli, C., Ghio, D., Hendow, M., Heylin, R., Jauhiainen, J.S., Jovanovic, K., Kierans, D., Mohan, S.S., Nikolova, M., Oruc, N., Ramos, M.P.G., Rössl, L., Sağiroğlu, A.Z., Santos, S., Schütze, T., & Sohst, R.R. (2024) MIrreM Public Database on Irregular Migration Flow Estimates and Indicators. Krems: University for Continuing Education Krems (Danube University Krems). https://doi.org/10.5281/zenodo.10813413. Siruno, L., Leerkes, A., Hendow, M. & Brunovksá, E. (2024) Working Paper on Irregular Migration Flows. MIrreM Working Paper No. 9. Krems: University for Continuing Education Krems (Danube University Krems). https://zenodo.org/records/10702228