Preeclampsia (PE) is a multisystemic and placental inflammatory disease that causes maternal and infant health issues. As one of the active components in peony root extract, paeonol (Pae) exerts anti-apoptosis and anti-inflammatory effects. Nonetheless, the protective role of Pae in PE has not yet been characterized. A mouse model of PE was constructed through tail vein injection of 1 mg/d phosphatidylserine/dioleoyl-phosphatidycholine suspension. The levels of inflammatory cytokines in the placenta were examined via enzyme-linked immunosorbent assay (ELISA). The mRNA levels of inflammatory cytokines (TNF-α, IL-6, IFN-γ, and IL-4) and apoptosis markers (Bax, Bcl-2, and caspase-3) were tested using quantitative reverse transcriptionpolymerase chain reaction (qRT-PCR). Western blot analysis was performed to detect the protein levels of apoptosis markers and Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway-related molecules. Here, Pae repressed the inflammatory response in the placenta of PE-like mouse models, as demonstrated by the decreased concentrations and mRNA levels of TNFα, IL-6, and IFN-γ and the increased concentrations and mRNA levels of IL-4. Apoptosis in the placentas of PE-like mouse models was attenuated by Pae, as manifested by the downregulated mRNA and protein levels of Bax and cleaved-caspase-3 and the upregulated Bcl-2. Administration of Pae inhibited the phosphorylation of JAK2 and STAT3 in the placental tissues of PE mice. The JAK2/STAT3 pathway agonist (SC-39100) reversed Pae treatment-mediated suppression of placental inflammation and apoptosis in PE mice. Overall, Pae inhibits the JAK2/STAT3 signaling pathway to attenuate placental inflammation and apoptosis in PE mice.