Background: Vitamin D deficiency is highly prevalent among the Omani population, driven by factors such as urbanization, technology‐driven lifestyles, reduced physical activity, limited sun exposure, unhealthy eating habits, and genetic predispositions. Despite the year‐round availability of sunlight, there is limited understanding of the specific causes of this deficiency and effective strategies to mitigate it.Aim: This study aimed to develop and validate a knowledge, attitude, and practice (KAP) questionnaire on vitamin D and measure the KAP levels among students at Sultan Qaboos University (SQU) in Oman to inform preventive and educational measures.Methodology: A cross‐sectional study was conducted using a newly developed, self‐administered KAP questionnaire distributed online to a random sample of 1034 Omani students enrolled in various degree programs at SQU. The questionnaire was developed following a standardized protocol, including a literature review, focus group discussions, and expert input. Validity and reliability were assessed using Cronbach’s α coefficient (α ≥ 0.70), and normality was examined with the Shapiro–Wilk test. The 54‐item questionnaire was divided into three domains: general knowledge of vitamin D, nutritional knowledge, and attitudes and behavior toward sun exposure. Descriptive and variance analyses were performed, with qualitative data expressed as numbers and percentages.Results: The questionnaire demonstrated good internal consistency (Cronbach’s α = 0.8057). Only 20.6% of the students had a good level of knowledge, 62% had an average level, and 17% had a poor level regarding vitamin D and its importance. The mean scores were 8.43 for general knowledge, 5.83 for nutritional knowledge, and 8.09 for attitudes and behavior toward sun exposure.Conclusions: The constructed questionnaire showed satisfactory validity and reliability. The study identified a generally poor level of knowledge about vitamin D among students, highlighting the need for targeted educational strategies to improve awareness and promote better health outcomes.