Though postpartum family planning helps women to achieve the recommended birth interval before next pregnancy, its utilization in Ethiopia is low. Understanding drivers and barriers is key to improve postpartum family planning uptake. The aim of this systematic review and meta-analysis is to analyze and summarize predictors of postpartum family planning uptake, during the first year after birth, in Ethiopia. We conducted a systematic review and meta-analysis of observational studies published in English before April 16, 2021. We searched electronic sources like PubMed, MEDLINE, CINHAL Embase, Google and supplemented it with manual search. Two reviewers appraised independently the studies using the Joanna Briggs Institute Quality Assessment Tool for the observational studies. Data synthesis and analysis were conducted using Review Manager Version 5.3. The Cochrane Q test statistic and I2 tests were used to assess the heterogeneity among the included studies. A random-effects and fixed effect model were used to calculate pooled Odds Ratio and its 95% CI. A total of 22 studies were included in the review. Better educational status of women[OR = 2.60; 95% CI: 2.15, 3.14], women’s marital status [OR = 4.70; 95% CI: 1.51, 14.60], resumption of sexual intercourse [OR = 6.22; 95% CI: 3.01, 12.86], menses return [OR = 3.72; 95% CI: 1.98, 6.99], PPFP discussion with partner [OR = 2.53; 95% CI: 2.00, 3.20], women’s previous PPFP information [OR = 4.93; 95% CI: 2.26, 10.76], PPFP counseling during ANC [OR = 3.95; 95% CI: 2.50, 6.23], having PNC [OR = 4.22; 95% CI: 2.80, 6.34], having experience of modern contraceptive use [OR = 2.90; 95% CI: 1.62, 5.19], facility birth [OR = 6.70; 95% CI: 3.15, 14.25], and longer interval after last delivery [OR = 0.37; 95% CI: 0.32, 0.43] were significantly associated with modern contraceptive uptake during postpartum period. Our systematic review identified modifiable factors and estimated their association with PPFP uptake. Since most of these factors are related to reproductive health characteristics and MNCH services, integrating PPFP into MNCH services particularly at primary health care unit may improve contraceptive uptake during postpartum period. Systematic review registration: PROSPERO: 2020: CRD42020159470.