Encyclopedia of (Hadron- and) Particle Physics will be a brand new, up to date reference work consisting of approximately 180 articles, headed up by an editorial board of world-leading hadron- and particle physicists. It will provide a first point of entry to the literature for all graduate/post-graduate students and early career-researchers working in and studying physics, especially those with an interest in hadron- and particle physics within the standard model and beyond. It will also be indispensable to all serious readers in the interdisciplinary areas (astrophysics, nuclear physics, particle therapy, accelerator physics) where particle physics is of utility. With a clear and logical template binding all chapters, content will be divided into the following six sections, each of which will contain chapters written by leading scientists who have pursued theoretical tools and methods and/or gathered and evaluated the most important data published within the field: Section 1: General Concepts of Particle Physics. This will provide an overview on general concepts that play a major role in every area of hadron and particle physics. Section 2: Hadron Physics. The strong interaction of quarks and gluons and the resulting hadron physics provides a broad field of interest with major discoveries (exotic hadrons) in the past decade. Understanding the strong interaction also provides the background for the search of physics beyond the standard model. Section 3: Lepton, Flavour and Higgs Physics. The electromagnetic and weak interaction of quarks, leptons and the Higgs particle provides a unique testing ground for the physics of the standard model with major advances in the past decades. Section 4: Neutrino Physics. This area has emerged in the past decade as a separate and highly innovative field with major discovery potential in the next years. Section 5: Beyond standard model physics. This section will provide introductions into the landscape of concepts of physics beyond the standard model including a broad variety of topics. Section 6: Experiments. Every young researcher struggles to get an overview on the large variety of ongoing and planned experiments in hadron and particle physics. Here will be introductions to general experimental concepts as well as an overview on all existing major international facilities and experiments. Advanced interactive features such as videos and 3D viewers are included, significantly increasing the practicality and learning outcomes for the modern-day reader for whom online usage is preferred. The result is the ideal one-stop foundational resource to the complex field of particle physics and an essential tool for physicists to refer to time and again.