Ḥasan bar Bahlul (Classical Syriac: ܚܣܢ ܒܪ ܒܗܠܘܠ ܐܠܐܘܐܢܝܐ, Ḥasan bar Bahlul; Arabic: الحسن بن بهلول الاواني الطيرهاني, al-Ḥasan ibn Bahlul al-Awāni al-Ṭirhāni) was a 10th-century Christian bishop and Syriac linguist.
His name has appeared in the list of bishops who supported Abdisho I's ascent to the patriarchy of the Church of the East in 963.
Based on his nisbah, bar Bahlul was a native of Ṭīrhān, a district now part of the city of Samarra, Iraq.
Bar Bahlul is mainly known for his comprehensive Syriac-Arabic dictionary.
He has also a number of other books that were lost on the biographies of Western and Eastern Syriac bishops and on the interpretation of dreams.