The placenta is a complex organ crucial for a successful pregnancy and the health of the developing fetus; however, the cellular and molecular architecture of the placenta is poorly understood. Here, we applied experimental and computational methods to dissect the molecular identity, spatial organization, and function of distinct cell types of the placenta at single-cell resolution. We integrated single-cell RNA-sequencing, single-cell spatial transcriptomics, and single-cell ATAC-sequencing to reconstruct a molecularly annotated and spatially resolved single-cell atlas of the placenta. Overall, this serves as a foundation for further studies of maternal-fetal interactions and development during pregnancy in health and disease.