The subject of this research is based on a survey of Ottoman mosques by the author in Greece, where around seven types were used in the Mosque design; three of them were very common and were separated across Greece (the single-unit- the T-plan- the "Eywan" Mosque- the quatrefoil plan), while three layouts were considered uncommon types of Ottoman mosques in Greece (the courtyard- the octagonal- the multi-domed mosques). In addition, uncommon elements were used in some mosques, such as the pogada roof of Ali PaşaHilmi in Rhodes Island. The research aims to study the unconventional plan layout typology of Ottoman mosques and identify the extent to which these layouts were connected with the known Ottoman architecture. By offering the common Ottoman styles in Greece in general, the author selects some examples of Mosques and analyzes their morphologies. As a result, the architectural typologies of the floor plan of historical mosques in Greece were identified. The study concluded several types of plans. The current paper revealed that the typology of plans in historical mosques in Greece related to the plan typology of Islamic known styles.