Background Similar to the side effects of cancer treatment, financial toxicity (FT) can affect the quality of life of patients, which has attracted increasing attention in the field of oncology. Despite the fact that the estimated prevalence and risk factors of FT are widely reported, these results have not been synthesized. Objectives This review is aimed to systematically assess the prevalence and risk factors of self-reported FT. Design Systematic review and meta-analyses. Data Sources A computer search of English literature was conducted using databases of PubMed, EMBASE, Web of Science, PsycINFO, and CINAHL, and reference lists of the qualified articles were also included between January 2010 and September 2021. Observational studies that reported the prevalence or risk factors of FT using subjective measures were included. Methods The systematic review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The risk of bias was assessed by the NIH observational cohort and cross-sectional study quality assessment tool. The data were extracted by two reviewers and listed in a descriptive table for meta-analyses. Results In the 22 studies available for meta-analyses of pooled prevalence of FT, the result was estimated to be 45% (95% CI: 38% to 53%, I-2 = 97.3%, P < 0.001) based on a random-effects model. The pooled analysis identified 9 potential risk factors of FT (7 in beta and 8 in OR): low income (OR = 2.48, 95% CI: 1.72 to 3.24, I-2 = 3.1%, P < 0.001), greater annual OOP (beta = -4.26, 95% CI: -6.95 to -1.57, I-2 = 0%, P = 0.002), younger age (OR = 2.05, 95% CI: 1.56 to 2.54, I-2 = 0%, P < 0.001), no private insurance (OR = 1.69, 95% CI: 1.02 to 2.37, I-2 = 0%, P < 0.001), unmarried (OR = 1.10, 95% CI: 0.95 to 1.25, I-2 = 53,3%, P < 0.001), nonwhite (OR = 1.59, 95% CI: 1.33 to 1.85, I-2 = 0%, P < 0.001), advanced cancer (beta = -4.74, 95% CI: -6.90 to -2.57, I-2 = 0%, P < 0.001), unemployed (beta = -2.90, 95% CI: -5.71 to -0.63, I-2 = 75,7%, P < 0.001), more recent diagnosis (OR = 1.31, 95% CI: 1.04 to 1.57, I-2 = 0%, P < 0.001). Conclusion This systematic review reported a pooled prevalence of self-reported FT of 45%. Low income, greater annual OOP (Out of pocket), younger age, unmarried, unemployed, nonwhite, no private insurance, advanced cancer, and more recent diagnosis constituted risk factors for self-reported FT. The research on risk factors for FT can provide a theoretical basis for medical staff to evaluate and intervene in the FT among cancer survivors.