Objective: This study aimed to determine the prevalence and identify associated factors of hepatitis B virus infection among pregnant women attending antenatal care (ANC) follow-up. Methods: An institution-based cross-sectional study was conducted from March 04 to April 03, 2020. A total of 381 women were selected using systematic random sampling after every two consecutive women. Structured and interviewer administered questionnaire was used to collect the data. A 2 ml of venous blood sample was drawn from each participant. The plasma was separated from the collected blood samples and was analyzed using a rapid hepatitis B surface antigen (HBsAg) kit to determine hepatitis sero status. Data were entered into the EPI-Data version 3.1, then exported to the statistical package for social sciences version 25 software and analyzed. Multivariable logistic regression was performed to identify independent predictors of HBsAg B seroprevalence at a p-value <0.05. Results: The prevalence of HBsAg sero-positivity among pregnant women was 6.6%, 95% CI (4.2, 8.9). History of hosptal admission (adjusted odds ratio (AOR) = 4.11; 95% CI = 1.33–12.71), surgical history (AOR = 6.8; 95% CI = 1.93–23.93), history dental procedures (AOR = 4.93; 95% CI = 1.31–18.53), and body tatoo practices (AOR = 6.822; 95% CI = 1.89–24.69) were found to be associated with HBsAg sero-positivity. Conclusion: This study found that HBsAg sero positivity among pregnant women in the study area was in intermediate edemicity. Factors such as history of hospital admission, history of surgery, history of dental procedures, and body tattoo practices were found to be associated with HBsAg sero-positivity. The government of Ethiopia should strengthen screening of all pregnant women for HBV as a part of routine ANC in ANC clinics and treating if they are positive to prevent mother to child transmission.