Undoubtedly, Sīmurgh is one of the most important and attractive Ishraqi (Illuminationist) and gnostic symbols in the Islamic-Iranian civilization. The traces of this mythical bird can also be found in Avestan and Pahlavi texts as a near-stationed and heaven-residing bird as well as the name of a prominent philosopher in Zoroastrian philosophy. The correct pronunciation of the world Sīmurgh is mərəyō saēnō in Avesta, sēnmurw and saeno muruk in Pahlavi language, and siræng in some Persian texts. Orientalists have translated this word into eagle and royal falcon in English. Perhaps the translation of Sīmurgh into eagle is rooted in translations’ focus on the word syena in Sanskrit, which means eagle in this language. Admittedly, this Sanskrit word is quite similar to the Avestan saena. Suhrawardī has talked about sīmurgh in different parts of his works such as in the treatises of Ṣafīr-i Sīmurgh, ‘Aql-i surkh, and Fī ḥālat al-ṭufullīyah. In ‘Aql-i surkh, following an innovative approach and method of interpretation, he discusses sīmurgh’s support of Rostam in his war with Esfandiar; in Ṣafīr-i sīmurgh he explains the virtues of sīmurgh in the Introduction to the treatise, and in the last treatise he elaborates on sīmurgh’s living in heaven. Suhrawardī’s method of discussion in these works reveals the place and holiness of this bird in his mind and language and, most importantly, the depth of his knowledge of ancient Iranian philosophy. In this paper, the author discusses the place of sīmurgh in Avestan and Pahlavi texts and Illuminationist philosophy.