Resumen: The study of non-degenerate set-theoretic solutions of the Yang-Baxter equation calls for a deep understanding of the algebraic structure of a skew left brace. In this paper, the skew brace theoretical property of solubility is introduced and studied. It leads naturally to the notion of solubility of solutions of the Yang-Baxter equation. It turns out that soluble non-degenerate set-theoretic solutions are characterised by soluble skew left braces. The rich ideal structure of soluble skew left braces is also shown. A worked example showing the relevance of the brace theoretical property of solubility is also presented. Idioma: Inglés DOI: 10.1016/j.aim.2024.109880 Año: 2024 Publicado en: Advances in Mathematics 455 (2024), 109880 [27 pp.] ISSN: 0001-8708 Tipo y forma: Artículo (Versión definitiva) Área (Departamento): Área Algebra (Dpto. Matemáticas)