AbstractComparative welfare state research as examined the outcomes of active labour market policies (ALMP) and work‐family reconciliation policies by and large been separately. As a result, potential complementarities between these policy areas have received scant attention empirically. Using macro‐level data, this study answers the question to what extent, and in which way, governments' efforts in ALMP and in early childhood education and care (ECEC) services are complementary to each other in promoting women's employment rates and reducing women's unemployment and inactivity rates in 30 OECD countries from 1985 to 2018. The article theorises about how the various policies that constitute a welfare state relate to each other, distinguishing between pluralism, complementarity and substitutability. These findings provide support for the notion of welfare pluralism, in the sense that ALMP and ECEC policies work together in improving women's employment rates in slightly different ways: ALMP achieve this through reducing women's unemployment rates, whereas ECEC also achieve lower inactivity rates for women. There was, however, more support for the notion of substitution rather than complementarity: the marginal benefits associated with an increase in either ALMP or ECEC were smaller in the context of large investments in the other policy. In other words, the highest rates of women's employment, and the lowest rates of unemployment and inactivity, are found in countries with large investments in both ALMP and ECEC, but such higher investments are associated with diminishing returns.