The diffusion of Iranian languages throughout a large part of the world, their deep recorded history, the remarkably intricate typological variation they show, and their extensive contact with languages belonging to different linguistic families make Iranian linguistics a fascinating and highly promising area for research in linguistic theory. Despite this remarkable scientific potential, however, and unlike the situation with nearly every other major language family, there are few collections of works focusing exclusively on languages of the Iranian family. The present volume is part of a current ongoing effort to address this gap, providing a theoretically informative and constructive venue for scholars working in Iranian linguistics. The twelve chapters of the current volume are selected from over 40 papers presented at the first North American Conference in Iranian Linguistics (NACIL1) held at Stony Brook University, April 28–30, 2017.