Parenting is recognized as a complex and stressful activity, which in recent years has been linked to the potential development of parental burnout among mothers and fathers. With the spread of COVID-19 around the globe, not only have situations of health emergency and economic difficulty emerged, but also tremendous impacts on individual lives and family role divisions, which continue to be experienced today. As lockdown measures have affected unemployment rates, financial insecurity levels, social support, amount of leisure time, and the number of caring responsibilities, parents are expected to be at higher risk for developing parental burnout. Co-parenting is presented as a factor which can mitigate the effect between COVID-19 lockdown measures and the levels of experienced parental burnout. Nevertheless, we argue that the role of co-parenting in association with the implications of COVID-19 on parental stress differs between men and women. As parenthood remains an activity that is largely gender-based, co-parenting is hypothesized to be of more crucial importance in attenuating the effect between COVID-19 lockdown measures and parental burnout for fathers in comparison to mothers. Our results confirm previous findings that COVID-19 has increased levels of parental burnout. The relationship between state-imposed COVID-19 lockdown measures and levels of parental burnout was not found to be significantly affected by co-parenting. However, when assessing this two-way interaction separately for men and women, we saw that this mitigating effect was significant for fathers and non-significant for mothers.