Electoral participation among immigrants is frequently examined through the lens of residence country integration policies and institutional access. However, immigrants arrive with embedded values and political attitudes developed through early political socialisation in their country of origin, which may influence their engagement with democratic institutions long after migration. Grounded in theories of political (re)socialisation – exposure, resilience, and transferability – and drawing on the ‘impressionable years’ argument in resilience theory, we hypothesise that pre-migration political culture influences electoral participation, but its influence varies across generations. Specifically, we examine how pre-migration exposure to different political regimes affects electoral behaviour and how the timing of arrival (before or after age 13) and the length of residence moderate these effects. To test the hypotheses, the analysis draws on European Social Survey (ESS) data (Rounds 5–11), covering 23 EU member states. We focus on citizens of foreign origin, including 14,216 first-generation, 3,620 1.5-generation (arriving before age 13), and 5,359 second-generation immigrants. Using additional measures from the Varieties of Democracy (V-Dem), we employ logistic regression models that integrate individual-level predictors with origin-country political culture, derived from migrants’ or their parents’ countries of birth. Our findings speak to all three strands of the political resocialisation framework. Early arrival and longer residence are associated with higher electoral participation, while pre-migration political socialisation continues to shape political behaviour after migration. Most notably, we find that first-generation immigrants socialised under authoritarian regimes exhibit higher electoral participation than their peers from democratic origins, suggesting the presence of a reactive mobilisation mechanism.