The aim of this study was to investigate the financial sustainability of retail food SMEs for the 2016–2021 period, in Romania, from the perspective of financial equilibrium and performance. A multivariate analysis was used, including a correlation analysis, a principal component analysis (PCA), and a cluster analysis. The empirical results show a positive link between the financial performance and financial equilibrium indicators. We employed the PCA in order to build a composite financial index using financial equilibrium indicators (ratios of liquidity, solvency, collection, and payment period) and financial performance indicators (Return on Assets and Return on Equity). The results show that financial equilibrium and performance are the two main dimensions which the financial sustainability index (FSI) was constructed on. Taking into account the dimensions of financial sustainability, the analyzed SMEs were clustered in four homogeneous clusters. The research findings clearly demonstrated that the retail food SMEs with a good/acceptable financial sustainability also have a good/acceptable financial balance and performance situation. Furthermore, a significant part of the analyzed SMEs faces difficulties regarding financial sustainability, being characterized by the lowest values of FSI, determined by both an uncertain situation in terms of liquidity, leading to a financial disequilibrium, and a negative financial performance. Therefore, this research emphasizes some specific measures that need to be taken to boost financial sustainability of these businesses in the retail food sector.