The IEEE/ACM International Symposium on Microarchitecture® is the premier forum for presenting, discussing, and debating innovative microarchitecture ideas and techniques for advanced computing and communication systems. This symposium brings together researchers in fields related to microarchitecture, compilers, chips, and systems for technical exchange on traditional microarchitecture topics and emerging research areas. The MICRO community has enjoyed a close interaction between academic researchers and industrial designers, and we aim to continue this tradition at MICRO-53. Due to the COVID-19 pandemic, the MICRO 2020 edition will be a global online event. The Athens edition of MICRO has been rescheduled for 2021.