Low-income couples are at an increased risk for relationship instability and divorce, which can have residual impacts on coparenting between the two partners. Growing evidence suggests that brief online relationship education programs can be an effective tool for alleviating relationship distress among low-income couples. However, findings remain mixed when it comes to whether benefits from relationship-focused programs not explicitly addressing coparenting spillover to coparenting among those with children. This preregistered study sought to investigate whether couples participating in an evidence-based online relationship-focused intervention, the OurRelationship program, experienced improvements in coparenting during the coronavirus disease 2019 (COVID-19) pandemic. To expand on the existing literature, coparenting outcomes assessed included partners' gatekeeping behaviors in addition to coparenting satisfaction, given their important implications for partner involvement in parenting. We also examined the extent to which changes in coparenting were moderated by pre-post gains in relationship satisfaction, child gender, division of childcare, and pandemic disruptions. In a sample of 136 low-income couples (N = 272 individuals) and a one-group/pre-post design, we found medium-sized gains in relationship satisfaction (Cohen's d = .76) and small-sized improvements in all coparenting aspects assessed (|d|s = .29-.39). Couples with greater gains in relationship satisfaction experienced greater improvements in coparenting; further, coparenting changes were robust to other moderators. Taken together, findings suggested that brief online relationship education programs, such as the OurRelationship program, may be a promising option to improve coparenting among relationally distressed low-income couples with children during a global health crisis.