Culture significantly influences individual desires and behaviors, and this is particularly evident in Osun State, which boasts a rich cultural heritage. Understanding cultural determinism and its impact on consumer behavior is essential for Small and Medium Enterprises (SMEs) operating in Osun State, as it directly affects their performance. From Osogbo to Ilesha, culture shapes consumer responses to the products and services offered by SMEs. This study aimed to investigate two key objectives: the impact of cultural determinism on consumer behavior and its relationship with SME performance in Osun State. Two hypotheses were tested using a descriptive survey design. The study population consisted of 2,273 SMEs in Osun State, according to SMEDAN. A sample size of 317 was determined using the Krejcie and Morgan table, and data were collected from business owners through simple random sampling in three major towns: Osogbo, Ife, and Ilesha. Out of the 317 questionnaires distributed, 301 were suitable for analysis. The findings suggest that SMEs in Osun State are significantly influenced by cultural beliefs, and these cultural factors must be considered when establishing and managing a business. The study recommends that SMEs in Osun State pay close attention to cultural beliefs at the individual, group, and societal levels to enhance their performance.