This book constitutes the refereed proceedings of the 11th International Tbilisi Symposium on Logic, Language and Computation, TbiLLC 2015, held in Tbilisi, Georgia, in September 2015. The 18 papers in this book were selected from the invited submissions of full, revised versions of the 37 short papers presented at the conference, and one invited talk. Each paper has passed through a rigorous peer-review process before being accepted for publication. The biennial conference series and the proceedings are representative of the aims of the organizing institutes: to promote the integrated study of logic, information and language. The scientific program consisted of tutorials, invited lectures, contributed talks, and two workshops.