Introduction: Pre-pregnancy obesity is a significant public health concern with profound implications for maternal and child health. The burgeoning evidence suggests that maternal obesity prior to conception is intricately linked with an increased risk of gestational complications, as well as with adverse neonatal outcomes. Furthermore, the long and short-term health of offspring, including the risk of early motor development impairment, obesity, and metabolic syndrome in childhood and adulthood, may be adversely affected as well. Addressing pre-pregnancy obesity is critical for improving overall maternal and child health outcomes, and therefore, the aim of this study was to evaluate the connections linking pre-pregnancy obesity with infants’ motor development within the first twelve months of infants’ lives. Material and Methods: This study included 200 mother–infant pairs divided into two groups based on their pre-pregnancy body mass index values. To assess infants’ early motor development, we used the Alberta Infant Motor Scale (AIMS) and evaluated the parameters of infants’ early motor development at the ages of three, six, nine, and twelve months. Results: Pre-pregnancy overweight/obesity was significantly associated with excessive gestational weight gain (p < 0.001), fetal macrosomia (p = 0.022), and a family history of diabetes and cardiovascular diseases (p = 0.048 and p = 0.041, respectively), as well as with all observed parameters of early motor development at the ages of three, six, nine, and twelve months: AIMS 3 months total (p < 0.001), AIMS 6 months total (p < 0.001), AIMS 9 months total (p < 0.001), and AIMS 12 months total (p < 0.001). Furthermore, pre-pregnancy overweight/obesity was a significant predictor for AIMS 6 months total (p = 0.043) and AIMS 6 months supination (p = 0.017). Conclusions: Pre-pregnancy obesity is a critical determinant of pregnancy outcomes and offspring early motor development, with possible far-reaching implications for children’s long-term well-being. Addressing this issue requires a comprehensive approach that includes preconception weight management, targeted interventions during the pregnancy and postpartum periods, and ongoing research to better understand the underlying mechanisms and develop effective strategies for prevention and management.