Background: Different life-threatening accidents can happen anywhere at any time in our daily livings. In this study, the knowledge about basic life support was below average among the non-medical population. Objective: The aim of the study was to assess basic life support knowledge and its associated factors among non-medical population attending the outpatient department. Methods: An institutional-based cross-sectional study was conducted from January 15/2020 to February 30/2020. Systematic random sampling was employed to get representative samples. Data were collected by using a structured interviewer-administered questionnaire. The data were analyzed by using a binary logistic regression model. Crude and adjusted odds ratios with the corresponding 95% confidence intervals were computed. Those variables with P-values of ≤0.05 were considered significantly associated with the outcome variable. Results: A total of 412 participants took part in the study with a response rate of 97.4%. Among the participants, 183 (44.4%) [95% CI (39.8-49.5)] were knowledgeable about basic life support. Age of 30-40 years was 50% [AOR=1.50, 95% CI (1.15-1.97)], the age of >40 years was 2.45 [AOR=2.45, 95 CI (1.53-3.91)], being male [AOR=2.22, 95% CI (1.41-3.49)], lived in the urban [AOR=1.66, 95% CI (1.25-3.56)], being trained [AOR=4.65, 95% CI (1.85-11.67)], ever heard about BLS and having exposure with the person in need of BLS [AOR=3.02, 95% CI (2.05-4.74)], and [AOR=2.59, 95% CI (1.69-3.98)] times more to be knowledgeable as compared with their counterparts. Conclusion: The finding of this study demonstrated that knowledge score of the participants was below average. Therefore, there has to be more to do so as to scale up the knowledge of the community for reducing preventable deaths from unexpected emergency situations.