Background: Nutrition in infancy and early childhood is a critical determinant of health outcomes and productivity of the individual throughout his/her life years. Thus, World Health Organization and United Nations Children’s Fund recommend initiation of complementary foods at 6 months to ensure optimal child growth and development. In Ethiopia, compliance to infant and young child feeding recommendations has been shown to be low despite adoption of high impact international policies and guidelines. Objectives: To assess the magnitude and associated factors of early initiation of complementary feeding among infants in Hawassa City, Southern Ethiopia, 2020. Methods: A community based cross-sectional study was conducted in Hawassa City in November, 2020. Systematic random sampling technique was applied to recruit 560 study participants; proportionally allocated to eight kebeles. Structured and interviewer administered questionnaire was used to collect data. The data were collected by six trained diploma nurses. The collected data were checked and entered to Epidata (version 4.6) and exported to Statistical Package for the Social Sciences (version 21) for analysis. Variables having a P-value of <0.05 in multivariable logistic regression were considered as statistically significant. Result: A total of 543 mothers/caregivers of infants were interviewed face to face giving a response rate of 97%. Approximately 38% of mothers initiated complementary foods before six months of age. After adjusting for confounders, maternal employment status [AOR (95%CI): 4.72 (2.84, 7.87)] and postnatal care checkup [AOR (95%CI): 1.92 (1.24, 2.97)]were associated with early initiation of complementary feeding. Conclusion: Thirty eight percent of mothers initiated complementary feeding before six months of infant's age. Postnatal care checkup and mother’s occupational status were significantly associated with early initiation of complementary feedings. Thus, increasing the coverage of postnatal care utilization and creating mother-friendly workplaces for breastfeeding mothers are of paramount importance to realize appropriate complementary feeding practices.