Internally displaced people (IDPs), uprooted by conflict, violence, or disaster, struggle with the trauma of violence, loss, and displacement, making them significantly more vulnerable to post-traumatic stress disorder (PTSD). Therefore, we conducted a systematic review and meta-analysis to assess the prevalence and associated factors of PTSD among IDPs in Africa. A comprehensive search of electronic databases was conducted to identify relevant studies published between 2008 and 2023. The search included electronic databases such as PubMed, CABI, EMBASE, SCOPUS, CINHAL, and AJOL, as well as other search sources. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Data were extracted using Microsoft Excel, and analysis was performed using STATA 17 software. The quality of the included studies was assessed using the JBI quality appraisal tool. A random-effects model was used to estimate the pooled prevalence of PTSD and its associated factors. The funnel plot and Egger's regression test were used to assess publication bias, and I2 test statistics was used to assess heterogeneity. The protocol for this review has been registered with PROSPERO (ID: CRD42023428027). A total of 14 studies with a total of 7,590 participants met the inclusion criteria. The pooled prevalence of PTSD among IDPs in Africa was 51% (95% CI: 38.-64). Female gender (OR = 1.99, 95% CI: 1.65-2.32), no longer married (OR = 1.93, 95% CI: 1.43-2.43), unemployment (OR = 1.92, 95% CI: 1.17-2.67), being injured (OR = 1.94, 95% CI: 1.50-1.50), number of traumatic events experienced [4-7(OR = 2.09, 95% CI: 1.16-3.01), 8-11 (OR = 2.09, 95% CI: 2.18-4.12), 12-16 (OR = 5.37, 95% CI: 2.61-8.12)], illness without medical care (OR = 1.92, 95% CI: 1.41-2.29), being depressed (OR = 2.97, 95% CI: 2.07-3.86), and frequency of displacement more than once (OR = 2.13, 95% CI: 1.41-2.85) were significantly associated with an increased risk of PTSD. The findings of this systematic review and meta-analysis highlight the alarming prevalence of PTSD among IDPs in Africa. Female gender, marital status, number of traumatic events, ill health without medical care, depression, and frequency of displacement were identified as significant risk factors for PTSD. Effective interventions and the development of tailored mental health programs are needed to prevent PTSD among IDPs, focusing on the identified risk factors.