This book constitutes the refereed proceedings of the 12th International Tbilisi Symposium on Logic, Language and Computation, TbiLLC 2017, held in Lagodekhi, Georgia, in September 2017.The volume contains 17 full revised papers presented at the conference from 22 submissions.  The aim of this conference series is to bring together researchers from a wide variety of fields in Natural language syntax, Linguistic typology, Language evolution, Logics for artificial intelligence and much more.