Teenage pregnancy and subsequent childbirth to women less than 20 years of age continue to be a major global public health concern in both developed and developing countries, affecting more than 16 million girls and young women, or an estimated 11% of all births worldwide. This study determined the factors influencing teenage pregnancy among teenage girls aged 13–19 attending ANC at KIU-TH, Bushenyi District. A cross-sectional study design was employed for this study. Quantitative data was collected using structured interviews. Questionnaire tools were checked for their accuracy and data completeness, then the data was coded and entered into Epi Info version 7, then exported into SPSS version 22.0 for analysis. A binary logistic regression model was used to identify the determinant factors. A collinearity diagnostic test was conducted using tolerance to check for collinearity between independent variables and the interaction effect. Variables in the bivariable analysis having a p-value <0.2 were considered for the multivariate analysis to adjust the confounders. The strength and presence of a statistical association were assessed by the OR, p-value, and 95% confidence interval (95% CI). Variables with a p-value ≤0.05 were considered statistically significant determinants of teenage pregnancy. The Hosmer-Lemeshow goodness-offit test (p = 0.9289) was used to assess the fitness of the model. A total of 310 adolescents were included in the study, with a response rate of 100%. The majority (39.7%) were aged 16–17, and more than half (59.0%) were from rural areas. The proportion of teenage pregnancies among study participants was 19.0. In the multivariate logistic regression model, age, residence, parents’ marital status, level of education, monthly income, substance abuse, history of use of contraceptives, age of first sexual contact, and awareness of safe sex were statistically significant. The study showed a high prevalence of teenage pregnancy. Age, residence, parents’ marital status, level of education, monthly income, substance abuse, history of use of contraceptives, age of first sexual contact, and awareness of safe sex were found to have a statistically significant association. Keywords: Teenage pregnancy, Childbirth, Girls, Marital status, Age.