Comprehensive HIV treatment and care makes it safer for women living with HIV (WLWH) to have the children they desire, partly through provision and appropriate use of effective contraception. However, nearly one third of WLWH in-care in a large Ugandan cohort became pregnant within 3 years of initiating ART and half of these incident pregnancies (45%) were unplanned. We therefore describe future pregnancy plans and associated factors among postpartum WLWH in rural southwestern Uganda in order to inform interventions promoting postpartum contraceptive uptake. This analysis includes baseline data collected from adult WLWH enrolled into a randomized controlled trial to evaluate the effect of family planning support versus standard of care at 12 months postpartum in southwestern Uganda. Enrolled postpartum WLWH completed an interviewer-administered questionnaire at enrolment. Among 320 enrolled women, mean age, CD4 count, and duration on ART was 28.9 (standard deviation [SD] 5.8) years, 395 cells/mm3 (SD = 62) and 4.6 years (SD = 3.9), respectively. One-hundred and eighty nine (59%) of women reported either personal (175, 55%) or partner (186, 58%) desire for more children in the next 2 years. Intentions to have more children was strongly associated with partner’s desire for more children (AOR = 31.36; P < 0.000), referent pregnancy planned (AOR = 2.69; P = 0.050) and higher household income > 150,000 Shs per month (AOR = 1.37; P = 0.010). Previous use of modern contraception (AOR = 0.07; P = 0.001), increasing age (AOR = 0.34; P = 0.012), having > 2 own children living in a household (AOR = 0.42; P = 0.021) and parity > 2 (AOR = 0.59; P = 0.015) were associated with reduced odds of pregnancy intention. Our findings highlight the role male partners play in influencing pregnancy intentions postpartum and the importance of engaging men in sexual and reproductive health counselling about child spacing for the health of women, children, and families. This should be addressed alongside key individual-level social, demographic, economic and structural factors within which couples can understand risks of unplanned pregnancies and access effective contraceptive methods when they need or want them.