The world's mid-ocean ridges form a single, connected global ridge system that is part of every ocean, and is the longest mountain range in the world. Geologically active, mid-ocean ridges are key sites of tectonic movement, intimately involved in seafloor spreading. This coursebook presents a multidisciplinary approach to the science of mid-ocean ridges – essential for a complete understanding of global tectonics and geodynamics. Designed for graduate and advanced undergraduate students, it will also provide a valuable reference for professionals in relevant fields. Background chapters provide a historical introduction and an overview of research techniques, with succeeding chapters covering the structure of the lithosphere and crust, and volcanic, tectonic and hydrothermal processes. A summary and synthesis chapter recaps essential points to consolidate new learning. Accessible to students and professionals working in marine geology, plate tectonics, geophysics, geodynamics, volcanism and oceanography, this is the ideal introduction to a key global phenomenon.