Background <p>Residential students are particularly vulnerable to Dengue Fever (DF) due to overcrowding and poor sanitation in dormitories, yet limited studies have focused on this group.</p> Objective <p>To assess the knowledge, attitude, and preventive practices (KAP) toward DF and their association with socio-demographic factors among residential students of a public university in Dhaka.</p> Methods <p>A descriptive cross-sectional study was conducted among 405 residential university students (mean age = 22 ± 2 years) using a semi-structured questionnaire.</p> Results <p>All respondents were aware of dengue fever; however, only 2% accurately identified its symptoms, and none reported taking appropriate actions during infection. Fewer than 30% used mosquito control measures such as coils, window screens, sprays, or repellents. We observed a significant association between attitude and preventive practices (<i>p</i> = 0.011). Older students (≥ 22 years) demonstrated better knowledge (OR = 1.25; <i>p</i> = 0.03), while females exhibited more positive attitudes (OR = 5.72; <i>p</i> = 0.001) and were more likely to engage in preventive practices (OR = 0.35; <i>p</i> = 0.001). Higher family income (OR = 0.59; <i>p</i> = 0.02), greater monthly expenditure (OR = 0.65; <i>p</i> = 0.04), and having fewer roommates (attitude: OR = 2.45; <i>p</i> = 0.001; practices: OR = 0.65; <i>p</i> = 0.001) were also associated with more favorable attitudes and practices.</p> Conclusions <p>Overall, the findings indicate an apparent disconnect between knowledge, attitudes, and actual preventive practices against DF. Tailored strategies that address social and environmental factors may be more effective in promoting comprehensive preventive measures.</p>