Brucellosis remains an important zoonotic disease in southern Saudi Arabia; however, community-level knowledge, risk-related practices, and information pathways in Najran City are insufficiently characterized. This study assessed brucellosis-related knowledge, attitudes, practices, and information pathways among adults in Najran City to inform locally relevant One Health interventions. In this cross-sectional survey, adults were recruited using stratified time–location (venue-based) sampling across community and exposure-relevant sites in Najran City. A total of 608 adults completed a structured interviewer-administered questionnaire. Composite scores were calculated for knowledge (0–21), attitude (0–22), practice (0–64), and information-source breadth (0–6). Descriptive statistics, group comparisons, correlation analyses, and multivariable linear regressions were performed. The findings suggest that participants more commonly relied on interpersonal social networks, especially family and friends, for information related to brucellosis (53.9%), whereas formal sources were less commonly reported, including health professionals (7.9%), media (4.6%), internet sources (3.3%), educational institutions (2.0%), and agricultural or veterinary organizations (1.3%). Mean knowledge scores were moderate (10.7/21), attitudes were generally favorable (19.5/22), and practice scores were moderate (36.6/64). Exposure-related behaviors remained common, particularly the consumption of unpasteurized milk or dairy products (56.6%). The breadth of information sources showed a moderate positive correlation with knowledge (rho = 0.561), whereas attitude showed only small positive correlations with knowledge and practice. Finally, knowledge was weakly and inversely correlated with practice. Among adults recruited in this venue-based sample, favorable attitudes did not consistently correspond to safer practices. These findings support practical One Health interventions, including coordinated veterinary–public health messaging on animal abortion events, safe-dairy guidance at points of sale and community venues, workplace-based training for livestock-contact groups, and referral pathways linking suspected animal cases with veterinary services and human care-seeking. Because recruitment was venue-based and non-probability, the results should be interpreted as descriptive and hypothesis-generating rather than population-representative; however, they still identify practical communication and service-delivery priorities for future intervention studies in Najran.