Objective: To evaluate the effectiveness of an ergonomic infant carrier for increasing postpartum parent-infant physical contact and reducing postpartum depression risk. Design: A randomized two-arm, parallel-group trial. Setting: Study participants’ homes from February 2018 to June 2019. Population or Sample: 100 participants in an income-constrained urban community in the United States. Methods: At 30-weeks gestation, 50 participants were randomly assigned to receive an ergonomic infant carrier and instruction on use (intervention), and 50 participants were assigned to a waitlist (control). Follow-up data were collected at 6-weeks postpartum from 78 participants (intervention n = 41; waitlist control n = 37). Main Outcome Measures: Edinburgh Postpartum Depression Scale (EPDS) score and extent of infant carrier utilization. Results: Participants in the carrier condition reported using their carriers for an average of 1.95 hours per day ( SD = 1.59) with participants in the intervention condition using an infant carrier significantly more often at 6-weeks (β = 2.69, SE = .347, p < .001, 95% CI = 2.08-3.41). The intervention group reported significantly fewer depressive symptoms at 6-weeks postpartum than the waitlist control group (β = -.541, p = .042). Participants who used an infant carrier more hours per day reported significantly fewer depressive symptoms (β = -1.60, SE = .069, p = .019, 95% CI = -.30 to -.025). Conclusions: An infant carrier intervention reduced postpartum depression at 6-weeks postpartum, with a significant dose-response association where increased infant carrier use predicted decreased postpartum depression symptomology. Funding: ErgoBaby donated all infant carriers used in this study but did not participate in any part of the research.