This study examines whether health inequalities exist between lone and cohabiting mothers across Europe, and how these may differ by welfare regime. Data from the European Social Survey are used to compare self-rated general health, limiting longstanding illness and depressive feelings by means of a multi-level logistic regression. The 27 countries included in the analyses are classified into six welfare regimes (Anglo-Saxon, Bismarckian, Southern, Nordic, Central-Eastern new-EU and Central-Eastern non-EU). Lone motherhood is defined as mothers not cohabiting with a partner, regardless of the legal marital status. Results indicate that lone mothers are more at risk of poor health than cohabiting mothers. This is most pronounced in the Anglo-Saxon regime for self-rated general health and limiting longstanding illness, while for depressive feelings it is most pronounced in the Bismarckian welfare regime. While the risk difference is smallest in the Central-Eastern regime, both lone and cohabiting mothers also reported the highest levels of poor health compared to the other regimes. Results also show that a vulnerable socioeconomic position is associated with ill-health in lone mothers, and that welfare regimes differ in the degree that they moderate this association.