This book presents the proceedings of 24th International Conference Series on Climbing and Walking Robots. CLAWAR 2021 is the twenty-fourth edition of International Conference series on Climbing and Walking Robots and the Support Technologies for Mobile Machines. The conference is organized by CLAWAR Association in collaboration with Kwansei Gakuin University on a virtual platform in Takarazuka, Japan, during 30 August-01 September 2021. CLAWAR 2021 brings new developments and new research findings in robotics technologies within the framework of "Robotics for Sustainable Future". The topics covered include biped locomotion, human-machine/human-robot interaction, innovative actuators, power supplies and design of CLAWAR, inspection, legged locomotion, modelling and simulation of CLAWAR, outdoor and field robotics, planning and control, and wearable devices and assistive robotics. The intended readership includes participants of CLAWAR 2021 conference, international robotic researchers, scientists, professors of related topics worldwide, and professors and students of postgraduate courses in Robotics and Automation, Control Engineering, Mechanical Engineering, and Mechatronics.