Engineering Materials, Structures, Systems and Methods for a More Sustainable Future comprises 275 papers that were presented at SEMC 2025, the Ninth International Conference on Structural Engineering, Mechanics and Computation. This event, held in Cape Town (South Africa) from 1 to 3 September 2025, was attended by around 300 participants from 42 countries worldwide. The Proceedings are divided into 15 sections. The various topics may be grouped into five broad categories covering: (i) the mechanics of materials, solids and structures; (ii) numerical modelling, computational simulations and experimental testing; (iii) analysis, design and construction in the traditional engineering materials; (iv) innovative engineering materials, structures and methods; (v) maintenance, long-term performance, life-cycle considerations and sustainable construction. Engineering Materials, Structures, Systems and Methods for a More Sustainable Future will be of interest to civil, structural, mechanical, marine and aerospace engineers, as well as planners and architects. Two versions of the papers are available: full papers of length six pages are included in the e-book, while short papers of length two pages, intended to be concise but self-contained summaries of the full papers, are in the printed book.