The XVIII edition of OECS, the International Conference on Optics of Excitons in Confined Systems (OECS 18), will take place in Lecce (Italy) from 12 to 16 of June 2023. OECS is a bi-annual conference that gathers scientists interested in the areas of optical excitations of semiconductors with specific attention on the physics of excitons, trions and collective excitations in different materials and photonic nanostructures. Moreover, the conference will cover aspects related to the onset of coherent phenomena and light-matter interactions, quantum optical properties and many-body physics as well as optical properties of emerging new materials. In this edition a particular attention will be given to young researchers and PhD students which are encouraged to participate in order to promote discussions and collaborations on new ideas and challenges arising in the community. In addition to the oral contributions an opportunity to present their work will be given to the best posters in an elevator pitch session.