Government budget allocations within budget execution are important in pushing the agricultural transformation agenda in Tanzania. However, agriculture public expenditure review studies show that with the exception of a few geographical areas in Tanzania, government budget allocations have generally been insufficient to bring about the desirable transformation from subsistence to commercial agriculture. Thus, this paper investigates the pivotal role of government budget allocations within budget execution in facilitating the commercialisation of maize, a crop that is both a major food and cash crop in Tanzania. It also assesses the factors that affect the performance of budget allocations. The descriptive survey design was employed whereby a cross-sectional survey was conducted to collect data from 180 local government officials in the Mbeya and Songwe regions that were sampled in the southern highland regions. Data was analysed through descriptive statistics and multiple regression using Statistical Package for Social Sciences (SPSS) software. The mean and standard deviation were used to measure budget allocations via the interpretation of means by Weak (Wk) and Strong (St). The findings show that the means of budget allocations were strong, and all four variables under it exerted a positive influence on maize commercialisation as measured through market participation. From the parameter estimates, standardised beta coefficient values were 0.468, 0.091, 0.030 and 0.167, respectively. In addition, the findings also show and confirm the requirement of the Maputo Declaration of 2003, which was reiterated by the Malabo Declaration of 2014, for governments in Africa to allocate at least 10% of their national budgets to agriculture. Based on the findings, the researchers conclude that effective and efficient budget allocations within budget execution are essential for achieving government development goals and objectives, including the transformation of agriculture from subsistence to commercial. It is recommended that the government should strengthen the budget execution process at all levels of government