From ancient Greece till the present, the golden ratio has been considered one of the most significant criteria of beauty in art and architecture. Architectural forms are part of the visual language that is bound by the rules of geometry and proportion. This study aims to identify the extent to which contemporary mosques in the city of Erbil utilize the golden ratio in the aesthetics of their facades. The research attempts to answer the question: was the golden ratio implemented in designing the facade of contemporary mosques in Erbil? The study adopted a mixed quantitative and qualitative analysis method. To achieve the study's aim and answer its questions, six mosques built in the last decade in Erbil were selected. Qualitatively, survey and documentation followed. Quantitatively, Phi matrix software, AutoCAD, and graphic software were applied as a mathematical approach. The study concluded that only one case used the golden ratio in the design of its façade by 100%, while it did not exceed 75% in most other mosques. The study draws the attention of designers and architects in the field of mosque architecture to the adoption of the golden ratio in the designs of mosque facades because of its role in achieving the aesthetic aspect.