The 46th International Symposium on Symbolic and Algebraic Computation (ISSAC2021) was held in Saint Petersburg, Russia, from July 18 to 23, in a hydrid mode with both online and in-person participants from different countries. At this conference, the ACM Special Interest Group on Symbolic and Algebraic Manipulation (SIGSAM) presents the ISSAC2021 Distinguished Paper Award to Shaoshi Chen, Ruyo...