Access to safe food is considered a basic human right, but food-borne disease presents a significant public health concern globally. The problem is exacerbated in low- and middle-income countries. Due to the rise in urbanization and the popularity of street food in low- and middle-income countries, understanding the Knowledge, Attitude, and Practice (KAP) of street food vendors is crucial to ensuring food safety. Therefore, this review was aimed to estimate the pooled proportion of KAP of street food vendors toward food safety and its associated factors in low- and middle-income countries. A comprehensive search of published studies before January 30, 2023, was identified using databases like PubMed/MEDLINE, Cochrane Library, HINARI, Science Direct, and African Journals Online, as well as other sources. The preferred reporting items for systematic reviews and meta-analysis guidelines were followed. Data were extracted using Microsoft Excel, and analysis was performed using STATA 14/SE software. The quality of the included studies was assessed using the Joanna Briggs Institute’s quality appraisal tool. A random-effects model was used to estimate the pooled proportion of KAP of street food vendors toward food safety and associated factors. The funnel plot and Egger’s regression test were used to assess publication bias, and I2test statistics were used to assess heterogeneity. Furthermore, sensitivity analysis and subgroup analysis was also conducted. In this study, fourteen eligible studies with a total of 2,989 study populations were included. The pooled proportions of good knowledge 62% (95% CI: 51–73), positive attitude 66% (95% CI: 47–86), and good practice 51% (95% CI: 36–65) toward food safety were found among street food vendors. Being of secondary school education (OR = 5.95, 95% CI: 4.05–7.85), having training in food safety (OR = 4.64, 95% CI: 2.62–6.67), having a higher monthly income (OR = 2.98, 95% CI: 1.06–4.9), and having good knowledge of food handling (OR = 2.26, 95% CI: 1.17–3.16) were found to be associated factors in the food safety practice of street food vendors. Based on the findings of this study, there was a significant gap in the KAP of street food vendors toward food safety. Therefore, the provision of training and strengthening health education about food safety are invaluable strategies for improving food safety.