The overarching theme of my Ph.D. thesis is migrant assimilation in the labor market in Europe. Given its comparative nature, I studied this topic from various angles using internationally comparable datasets. In the first paper, we used the linear probability model (LPM) to estimate the degree of immigrant labor market assimilation, focusing on the probability of being employed by gender, in 16 European countries between 1999 and 2018, using the EU Labour Force Survey (EU-LFS). The results show that in most countries, female migrants start with a larger employment gap but converge more rapidly than male migrants. However, there are significant variations between countries. To understand the sources of these variations, we analyzed the correlation between our estimates and country-level macroeconomic, institutional, and cultural variables. For example, the findings indicate that higher labor market rigidity slows down the assimilation of both male and female immigrants. Since local attitudes and labor market institutions appear to influence female employment assimilation, introducing tailored policies at the sub-national level is recommended. In the second paper, I used the cross-sectional version of the EU Statistics on Income and Living Conditions (EU SILC) to estimate the effect of education on labor market outcomes in 23 European countries for both native-born individuals and migrants. Given that education is endogenous in this identification, I used the change in the length of compulsory schooling as an instrument variable (IV) for the years of education. The study reveals diverse patterns in the effects of compulsory schooling reforms and returns to compulsory education depending on one’s migration status and the destination country. While reforms in longstanding destinations were effective in raising the average education level of the native population, for the migrant population, the effect was mostly positive in recent and emerging destinations. While some reforms led to discernible increases in the average years of schooling among migrant populations, the returns on education for migrants remain limited. This underscores the pivotal role of more tailored education policies in facilitating the integration of migrants into their destination countries. In the third paper, I constructed treated and control groups based on individuals observed over time using the longitudinal feature of the European Community Household Panel (ECHP). Using propensity score matching based on pretreatment variables, I estimated the average treatment effect on the treated (ATT) health shocks on migrants’ labor market outcomes in six European countries. The effect of health shocks on migrant employment is more pronounced in Portugal than in other countries.