This volume contains the proceedings of PLACES 2024, the 15th edition of the Workshop on Programming Language Approaches to Concurrency and Communication-cEntric Software. The PLACES workshop series offers a forum for researchers from different fields to exchange new ideas about the challenges of modern and future programming, where concurrency and distribution are the norm rather than a marginal concern. PLACES 2024 was held on 6 April 2024 in Luxembourg City, Luxembourg. The programme included keynote talks by Mariangiola Dezani-Ciancaglini and Peter M\"uller, presentations of five research papers, and three talks about preliminary or already-published work that could foster interesting discussion during the workshop. These proceedings contain the five accepted research papers, the abstracts of the keynote talks, and a list of the other contributions.