Non-Timber Forest Products (NTFPs) are products or services other than timber that is produced in a forest and of course, are indispensable parts of the livelihood strategy of the forest’s adjoining communities. Their economic potentials necessitated the need for research to be carried out on its production and constraints facing its supply in the study area. Therefore, constraints to NTFPs’ supply in Ago-Owu forest reserve and its environment were investigated. Three communities (Mokore, Ajegunle and Alabameta) were randomly selected communities of the identified study area (Mokore, Ajegunle, Alabameta, Elewe, Alaguntan and Okodowo) identified communities in the study area. Their populations were sought for and samples were drawn in proportionate to their sizes: Mokore (50), Ajegunle (40) and Alabameta (20). This gave a total number of 110 respondents from which 105 questionnaires were derived for the investigations. A set of questionnaire was used to obtain data on source of NTFPs, commonly sourced NTFPs and constraints facing its supply in the study area. Data were analyzed using descriptive statistics and logit regression at α0.05. Majority of the respondents were male (69.1%) and 64.8% of them were within the age of 30-50 years. Also, most of the respondents were married (78.1%) and less than half of them (41%) had no formal education, but were predominantly farmers (72.4%). The major source of NTFPs in the study area was forest reserve (70.5%), while a total of seventeen (17) different NTFPs commonly sourced were documented. Constraints facing the supply of NTFPs included Climate change, Lack of finance for smooth running of the activities involved in the products’ supply and price fluctuation with odds-ratio of 9.87, 5.66 and 1.92 respectively. The study established the significance of the Ago-Owu forest reserve to the livelihood of the forest dwellers. However, there is need for the establishment of new plantations to fostering production of the products as well as serving as adaptation strategies against climate change. There is also an urgent need for the State Forestry Service/government to address their areas of concern pointed out in this study for bio-prospecting, economic well-being of forest dwellers and great advantage of boost in revenue propensity of Osun State.