Background: Chronic Toxoplasma gondii infection presents a unique immunological challenge during pregnancy, requiring a balance between the pro-inflammatory response needed for parasite control and the anti-inflammatory state vital for fetal tolerance. Interleukin-33 (IL-33), an alarmin cytokine, is a key immunomodulator; however, its profile in pregnant women with latent toxoplasmosis remains poorly understood. Objective: This study aimed to compare serum IL-33 levels between T. gondii-seropositive and seronegative pregnant Iraqi women and to investigate its relationship with the anti-T. gondii IgG antibody titer. Methods: A comparative cross-sectional study was conducted on 120 pregnant women (60 seropositive and 60 seronegative) attending Al-Elwiya Maternity Teaching Hospital in Baghdad from October 2024 to May 2025. Serum IL-33 levels were measured using a quantitative ELISA. Statistical analysis was performed using SPSS version 26.0. Results: Serum IL-33 levels were significantly higher in the T. gondii-seropositive group (Median: 85.5 pg/mL, IQR: 62.3-114.8) compared to the seronegative group (Median: 42.1 pg/mL, IQR: 30.5-58.9) (p < 0.001). This elevation was consistent across all trimesters. Furthermore, a weak but statistically significant positive correlation was found between serum IL-33 levels and anti-T. gondii IgG titers in the seropositive group (r = 0.289, p = 0.025). Conclusion: Chronic T. gondii infection in pregnant women is associated with a significant elevation in serum IL-33, which correlates with the humoral immune response.