| Honorific Prefix: | Bulbul-e-Bangla |
| Syed Rayhan ad-Din | |
| Religion: | Islam |
| Denomination: | Sunni |
| School: | Hanafi |
| Lineage: | Syed Nasiruddin |
| Birth Place: | Pail, Taraf, Greater Sylhet |
Syed Rayhān ad-Dīn (Bengali: সৈয়দ রায়হান উদ্দিন, Persian: {{Nastaliq|سید ریحان الدین) was a medieval Sufi author of Bengal.[1] His work gained recognition at the imperial court of Delhi, where he gained the nickname Bulbul-e-Bangālah (Persian: بلبل بنگاله; Nightingale of Bengal).[2]
Syed Rayhan ad-Din was born in the village of Poil of Taraf. Taraf was a renowned centre of Islamic education in the subcontinent during the medieval period.[3]
Rayhan wrote in the Persian language,[4] and among his prominent works is Khawābnāma (خوابنامه).[5] He also wrote his own version of the Masnavī-e-Gul-e-Bakāwalī (مثنوى گل بکاولی).[6]