The Eighth International Conference on Very High Cycle Fatigue (VHCF8) was held online and on-demand from July 5 to 9, 2021. Following the epoch-making findings of the 1980s regarding internal fatigue fractures in high-strength steel under numerous loading cycles, very high cycle fatigue (VHCF) has emerged as an unprecedented issue in materials strength. Today, the requirements for mechanical components and structures are increasingly demanding, as evidenced by new standards for automobile engines, marine engines, turbine structures, high-speed railway components, and more. Reliability against cyclic loading greater than 107 cycles is now regarded as one of the most critical aspects of strength design. Thus, an improved understanding of VHCF behavior—both in metallic materials and in polymers and composites—is essential for developing reliable fatigue life prediction methods. VHCF8 focused on this topic, building on the success of previous conferences: VHCF1 in 1998, in Paris; VHCF2 in 2001, in Vienna; VHCF3 in 2004, in Kusatsu; VHCF4 in 2007, in Ann Arbor; VHCF5 in 2011, in Berlin; VHCF6 in 2014, in Chengdu; and VHCF7 in 2017, in Dresden.