Background and AimBreast cancer is becoming a major public health concern globally, particularly in developing countries like Ethiopia. This study aimed to assess factors related to knowledge, attitude regarding breast cancer, and breast self‐examination (BSE) practices among female preparatory students in Addis Ababa, Ethiopia.MethodsA cross‐sectional study was conducted among 844 participants using a pretested self‐administered questionnaire in 2021 in Addis Ababa, Ethiopia. Binary and multivariable logistic regression analyses were employed to identify factors associated with the outcome variables. A level of significance was declared based on the adjusted odds ratio (AOR) with its 95% confidence interval and p ≤ 0.05.ResultsOf the participants, 41.6% demonstrated good knowledge, and 47% have positive attitudes regarding breast cancer and BSE. Only, 21.9% practiced BSE regularly. Low family income (AOR = 1.791; 95% CI, 1.140–2.813) and lack of BSE awareness (AOR = 2.051; 95% CI, 1.511–2.784) were found to be associated with poor knowledge. Negative attitude was found to be significantly related to Poor knowledge (AOR = 0.713; 95% CI, 0.522–0.973) and lack of BSE awareness (AOR = 0.413; 95% CI, 0.300–0.568).ConclusionMore than half of the participants had inadequate knowledge and negative attitudes toward breast cancer and BSE, with poor BSE practice. School‐based health education programs are needed to improve the participants' knowledge and attitudes.