INTRODUCTION: Despite the decrease in the global under-five mortality rate, the highest rates of mortality are reported in sub-Saharan Africa. More than one-third of all deaths among under-five children are either from lower respiratory tract infections, diarrhea, or malaria. Poor treatment-seeking behavior for fever among mothers of under-five children is a big concern in sub-Saharan Africa. However, the pooled prevalence of prompt treatment of fever and its associated factors among under-five children in the region using nationally representative data is not known. Therefore, the findings of this study will inform policymakers and program managers who work on child health to design interventions to improve the timely and appropriate treatment of fever among under-five children. METHODS: Data from the recent demographic and health surveys of 36 countries in sub-Saharan Africa conducted between 2006 and 2022 were used. A total weighted sample of 71,503 living children aged under five years with a fever was included in the study. Data extracted from DHS data sets were cleaned, recorded, and analyzed using STATA/SE version 14.0 statistical software. Multilevel mixed-effects logistic regression was used to determine the factors associated with the outcome variable. Intra-class correlation coefficient, likelihood ratio test, median odds ratio, and deviance (-2LLR) values were used for model comparison and fitness. Finally, variables with a p-value <0.05 and an adjusted odds ratio with a 95% confidence interval were declared statistically significant. RESULTS: The pooled prevalence of prompt treatment of fever among under-five children in sub-Saharan African countries was 26.11% (95% CI: 25.79%, 26.44%). Factors like maternal education [AOR = 1.18; 95% CI (1.13, 1.25)], maternal working status [AOR = 1.34; 95% CI (1.27, 1.41)], media exposure [AOR = 1.05; 95% CI (1.01, 1.10)], household wealth index [AOR = 1.13; 95% CI (1.06, 1.19)], distance to a health facility [AOR = 1.18; 95% CI (1.13, 1.23)], healthcare decisions [AOR = 1.34; 95% CI (1.01, 1.77)], visited healthcare facility last 12 months [AOR = 1.45; 95% CI (1.38, 1.52)], antenatal care attendance [AOR = 1.79; 95% CI (1.61, 1.99)], place of delivery [AOR = 1.55; 95% CI (1.47, 1.63)], and community-level antenatal care utilization [AOR = 1.08; 95% CI (1.02,1.14)] were significantly associated with prompt treatment of fever among under-five children. CONCLUSION: The pooled prevalence of prompt treatment of fever among under-five children in sub-Saharan African countries was low. Educated women, working mothers, having media exposure, rich household wealth status, perceiving distance to a health facility was not a big problem, making healthcare decisions with husband or partner, visiting healthcare facility in the last 12 months, antenatal care attendance, health facility delivery, and high community-level antenatal care utilization increase the odds of prompt treatment of fever. Therefore, women's empowerment, information dissemination through mass media, maintaining regular visits to healthcare facilities, and strengthening health facility delivery and antenatal care services are strongly recommended.