See main article: article and 2020 St. Petersburg Open. The tournament was played on a hard surface. Due to the ongoing COVID-19 pandemic and many ATP tournaments having been cancelled, this year's event was upgraded to ATP 500 level.
Daniil Medvedev was the defending champion, but lost in the second round to Reilly Opelka.
Andrey Rublev won the title, defeating last year finalist Borna Ćorić in the final, 7–6(7–5), 6–4.