The study analyzed sector differences in business structure on employment using secondary data obtained from the National Bureau of Statistical Register (2023) in Tanzania. The main objective was to examine how variations in business characteristics across sectors influence employment patterns. Specifically, the study assessed the relationship between firm age and employment size, tested whether mean employment differs between manufacturing and service sectors, and examined the association between business sector and firm size classification. Quantitative research approach was employed, utilizing descriptive statistics and inferential techniques including Pearson correlation, independent samples, t-test, and chi-square analysis, all conducted at a 5% significance level using SPSS. The findings revealed a significant negative relationship between firm age and employment size, indicating that newer establishments tend to employ more workers than older firms. Results also showed a statistically significant difference in mean employment between sectors, confirming that employment is not uniform across industries. Furthermore, a significant association was found between sector and firm size classification, demonstrating that the distribution of small, medium, and large firms varies by sector. These findings provide evidence to support sector-specific policies, encourage the growth of emerging firms, and promote data-driven strategies for enhancing job.