On behalf of the International Association of Mathematical Physics (IAMP), the International Scientific Committee, and the Local Organizing Committee we invite you to participate in the XX International Congress on Mathematical Physics to be held in Geneva, Switzerland from 2-7 August 2021. The International Congress on Mathematical Physics (ICMP), on its three year cycle, is the most important conference of the International Association of Mathematical Physics. It will be a major event, where new results and future challenges will be discussed, illustrating the richness and vitality of Mathematical Physics. ICMP 2021 will be preceded by the Young Researchers Symposium (YRS) from 29-31 July 2021.