Pregnancy can affect the mother's oral health, increasing their susceptibility to oral diseases that have been associated with harmful effects on the newborn. Despite the severity of oral diseases during pregnancy, the demand for dental care during the gestational period is low, which may improve with the participation of midwives in promoting oral health activities. The objectives of this study were: (i) to determine the knowledge, attitudes, and practices of Spanish midwives and midwifery students regarding oral health in pregnant women; and (ii) to identify the barriers faced by these healthcare professionals in addressing oral health promotion during pregnancy. An observational cross-sectional descriptive study was conducted. A total of 128 midwives and/or midwifery students ≥ 18 years old and of both sexes were invited to self-complete a questionnaire between January and April 2020. A total of 85 people participated in the study. Participants had a regular level of knowledge about oral health during pregnancy (overall knowledge score: 6.53), and although they were interested in activities that promote oral healthcare, their oral healthcare practices during pregnancy were limited. As midwives play an important role in promoting health, their training in oral healthcare could help to improve pregnant women's oral health.