Mosquito-borne diseases, such as malaria, yellow fever, dengue, and chikungunya, pose significant public health challenges, particularly in regions like Ogun State, Nigeria, where ecological and socio-demographic factors facilitate vector proliferation. This study aims to assess the knowledge, attitudes, and practices (KAP) related to mosquito-borne diseases among Ogun State residents, providing insights to guide targeted interventions. A cross-sectional survey was conducted with 450 respondents selected through a multistage sampling technique. Data on socio-demographic characteristics, knowledge, attitudes, and practices were collected using a structured questionnaire. Statistical analysis, including descriptive statistics, chi-squared tests, and linear regression, was performed using R software to identify associations between demographic factors and KAP indicators. The study population was predominantly young adults (mean age: 25.49 years), with more male participants (65.3%) and a nearly even urban-rural split. While 66.4% of respondents had heard of mosquito-borne diseases, only 34.7% and 36.7% identified Anopheles and Aedes mosquitoes as vectors. Preventive practices such as sleeping under mosquito nets (80.8%) were standard, but other measures, including eliminating stagnant water (46.4%) and using insecticides (40.3%), were less prevalent. Attitudes toward diagnostic testing were limited, with most respondents relying on symptomatic recognition rather than confirmatory testing. Significant associations were observed between demographics and KAP indicators. The findings highlight critical gaps in knowledge, attitudes, and practices related to mosquito-borne diseases in Ogun State. Targeted health education, improved access to preventive tools, and community engagement are essential to bridging these gaps and reducing the public health burden of mosquito-borne diseases.