Introduction Glaucoma is a global public health problem and it is the leading cause of irreversible blindness worldwide and the fifth cause of blindness in Ethiopia. Even though public knowledge of glaucoma is a key for early case identification and prevention of blindness, it is unknown in the study area, making provision of interventions difficult. Objective: To assess knowledge of glaucoma and associated factors among adults in Gish Abay town, Northwest Ethiopia, 2018 Methods: A Community based cross - sectional study design with systematic random sampling technique was used to select 630 adults. The study was conducted from April 25-May 05, 2018. Data was entered into Epi Info version 7 and was analysed by Statistical Package for Social Sciences version 23. Binary logistic regression model and adjusted odds ratio with 95% confidence level was used to identify the significant factors associated with knowledge of glaucoma. P–value ≤ 0.05 was considered statistically significant. Results: About 594 adults were participated with a response rate of 94%. Nearly 52% of the participants were females with median age of 28 years. The proportion of good knowledge was demonstrated in 68.9% [95% CI; 61, 75.9]. Educational status: secondary education [AOR; 4.01: 1.15, 13.94], college and above [AOR; 4.49: 1.31, 15.32], history of eye examination [AOR; 2.86: 1.05, 7.79] and younger age (18-22) [6.39: 1.82, 22.41] were positively associated with good knowledge of glaucoma. Conclusion and recommendation: The proportion of good knowledge of glaucoma was high. Better educational status, younger age, eye examination at least once in life and higher income level were associated with better knowledge of glaucoma. Recognizing the severity of glaucoma, enhancing knowledge is paramount at the community.