Preface This proceedings contents the papers accepted for presentation at SAOA 2015, the 1st Argentine Symposium on Ontologies and their Applications (Simposio Argentino de Ontologías y sus Aplicaciones), held on August 2-3, 2015 in Rosario, Argentina, at the Universidad Nacional de Rosario - Facultad de Ciencias Exactas, Ingeniería y Agrimensura (FCEIA-UNR). SAOA 2015 was part of the 44th JAIIO, the 44th Argentine Conference on Informatics, organized by SADIO. JAIIO is organized as a series of thematic symposia including topics such as software engineering, artificial intelligence, technology, agroinformatics, high performance computing, industrial informatics, free software, law, health, information society, and a students contest. The Argentine Symposium on Ontologies and their Applications aims at providing a meeting point among researchers from different fields as well as professionals from industries having interest on ontologies. SAOA encourages the submission of original contributions ranging from academic research to industrial and business applications having a significant impact as well as lessons learned and best practices in ontology development. This is the first national symposium on the topic of ontologies. We hope it will provide the motivation needed to advance research on this interesting and influential topic. We are very grateful to the authors for submitting their works, to all the program committee members for doing an excellent job and to all the people involved in the JAIIO organization, represented by Prof. Diego Milone, from Sinc(i) - FICH-UNL/CONICET, Prof. Pablo Granito, from CIFASIS - CONICET/UNR; and Prof. Rosita Wachenchauzer, President of SADIO, for providing the guidance and support along the way. Our special thanks are also addressed to the invited speakers Prof. Giancarlo Guizzardi and Prof. João Paulo Andrade Almeida. September, 2015 Horacio Leone Pablo Fillottrani