Objectives: Vitamin D deficiency is highly prevalent in Jordan and represents a significant public health concern. This study aimed to assess the knowledge, attitudes, and practices (KAP) of the Jordanian population regarding vitamin D deficiency. Methods: A cross-sectional study was conducted among Jordanian adults aged ≥18 years between October 2018 and January 2019. Data were collected using a structured, self-administered questionnaire. Results: Nearly all participants (99.7%) reported awareness of vitamin D. Media (53.6%) and educational institutions (45.9%) were identified as the primary sources of information. Most participants (82.6%) recognized sunlight as the main source of vitamin D, while 81.6% were aware of its role in preventing osteoporosis, and 78% believed that vitamin D deficiency causes bone and joint pain. However, knowledge of the recommended daily intake was notably low (13.9%). Although 60.4% of participants were not concerned about their vitamin D levels, attitudes toward sun exposure were generally positive. Approximately 72.3% reported enjoying sun exposure at least twice per week for ≤29 minutes, preferably during early morning hours, regardless of sunscreen use (42.8%). Positive practices included vitamin D supplementation (46.4%) and regular sun exposure (72.7%). Conclusions: Despite high awareness of vitamin D among Jordanians, gaps remain in knowledge regarding recommended intake and personal vitamin D status. Public health interventions focusing on education, supplementation, and food fortification are recommended to improve vitamin D status in Jordan.