Background <p>Non-hormonal intrauterine devices (IUDs) create an inflammatory uterine environment while oral contraceptives (OC) suppress ovulation and have different associations with ovarian cancer risk. We have evaluated the associations of&#xa0;these two contraceptive exposures with ovarian tumor immune infiltration.</p> Methods <p>This study assessed associations of IUD and OC use with tumor immune features via multiplex immunofluorescence in 24 ovarian tumor tissue microarrays from four case-control and two cohort studies. Multivariable-adjusted beta-binomial models estimated the odds of tumor T cell positivity by contraceptive history.</p> Results <p>High-grade serous tumors had the highest percentage of tumor cells positive for total T cells (CD3⁺ mean=3.4%, SD = 6.1) and each T cell subtype. Ever (vs. never) IUD use was modestly associated with increased cytotoxic T cell infiltration (CD3⁺CD8⁺ OR:1.14, 95% CI:0.99–1.32), which was stronger among those with a history of endometriosis, postmenopausal women, and smokers. Conversely, OC use ≥1 year (vs. never) was associated with lower cytotoxic T cell odds (CD3⁺CD8⁺ OR:0.89, 95% CI:0.79–1.00; <i>p</i>-het=0.008). Increased odds of terminal T cell exhaustion were observed for IUD use only (CD3⁺PD1⁺TIM3⁺ OR:1.53, 95% CI:0.99–2.36), which was stronger among those who had ever used genital powder or BMI &gt; 25 kg/m².</p> Conclusions <p>Pre-diagnostic contraception use may influence ovarian tumor immunity and may modulate cancer susceptibility.</p>