Research on migration intentions is relatively fragmented, traditionally drawing conclusions from relatively small survey samples, focussing on individual countries, or relying on public opinion polls which provide very few explanatory variables. This paper addresses these limitations by developing a multilevel model of an extensive range of macro, meso, and microdeterminants of migration intentions across different time frames. The paper utilises an online panel survey of 20,473 non-student respondents aged 16-35 from nine European Union countries. Ordinal multilevel modelling, with post-stratification weighting, is used to determine the key drivers of, and barriers to, migration intentions in both a pan-European model and nine separate nationalscale models. The findings confirm the significance of macro, meso, and micro factors. Although socio-economic factors emerge as powerful explanatory factors, non-pecuniary factors are also important, including sensation seeking. There are broad similarities in the findings across the separate national-level models but also differences in the relative importance of socio-economic, gender, and personality factors. Migration intentions were highly dependent on the decisionmaking time frame: 17% of respondents over 1 year, but 30% over 5 years, are likely to migrate or to have made firm plans to migrate. The rank ordering of the countries challenges the notion of there being a simple differentiation between the newer and older member states of the European Union.