Insight into the epidemiology of perinatal medication use during the COVID-19 pandemic is scarce. Therefore, a cross-sectional study using an anonymous web survey was performed in Ireland, Norway, Switzerland, The Netherlands, and United Kingdom (UK) to investigate the prevalence and type of medications used by pregnant and breast-feeding women during the first pandemic wave. Factors associated with medication use were estimated by logistic regression. In total, 8378 women participated (i.e., 3666 pregnant and 4712 breastfeeding women). Most responses were collected in Norway (34%) and The Netherlands (28%), followed by Switzerland (19%), Ireland (17%) and UK (2%). Participants were more often professionally active and more often had a higher educational level compared to the general birthing population in each country. Overall, approximately 60% of women reported having used at least 1 medication in the preceding 3 months. Daily and occasional use was reported by 34% and 42% of pregnant and 29% and 44% of breastfeeding women. The most prevalent ATC (Anatomical Therapeutic Chemical) categories were the nervous system, the respiratory system, the alimentary tract/metabolism, and the musculo-skeletal system. Paracetamol, ibuprofen, antacids, and cetirizine were the most frequently used medications. The rate of antibacterial use was lower than previously reported. Having a chronic illness, country, maternal age, SARS-CoV-2 testing, professional status and time since delivery were associated with medication use. In conclusion, perinatal medication use was highly prevalent during the first pandemic wave, underlining the importance of maintaining counseling efforts on medication use, even in times of disrupted healthcare services and/or limited resources.