Debates about immigration‘s role in addressing population aging typically concentrate on immigrant fertility rates. Moreover, standard projections account for migration‘s impact on overall population growth while largely overlooking how immigration might affect the fertility of the host population. In contrast, we show that forced immigration influences host country fertility as well. We investigate this relationship by examining the influx of refugees into T?rkiye following the onset of the Syrian civil war in 2011. Using two complementary instrumental variable strategies, we find robust evidence that host country fertility increases in response to forced migration. This result holds across three distinct datasets and is further supported by a corresponding rise in subjective fertility measures, such as the ideal number of children. Additionally, we explore four potential mechanisms and document significant heterogeneity in fertility responses among different subgroups of the local population. Our findings suggest that factors related to the labor market and norm transmission may help explain the observed increase in host country fertility.