Hydrogen (H2) gas has been considered a clean and sustainable energy source, representing a promising alternative to fossil fuels. However, the effective method for hydrogen production for large scale demand is still challenging; moreover, several production methods exist. Among these methods, water-splitting electrolysis using an electrocatalyst is an effective technique for efficient hydrogen production. Creating efficient, stable, and economical electrocatalysts is crucial for attaining high electrocatalytic hydrogen production through water splitting or electrolysis. This book chapter offers an overview of strategies and information for designing electrocatalysts with high performance in water splitting, emphasizing their activity, stability, and efficiency. It explains the key factors hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The design developments covered nanostructured electrocatalysts utilizing noble, non-noble (noble-free) metals, and metal-free electrocatalysts. It also covers innovative approaches and insights into the structure, composition, particle size, morphology, phases, doping, defects, substrates, and active sites of electrocatalysts designed to improve the activity and stability in the HER and OER. It outlines the challenges and opportunities in advancing active and resilient electrocatalysts for the HER and OER to enhance hydrogen production through water-splitting electrolysis.