Abstract Therapeutic options are urgently needed to fight the outbreak of a novel coronavirus (SARS-CoV-2), which causes the COVID-19 disease and is spreading rapidly around the world. Drug repurposing can significantly accelerate the identification of drug candidates suitable for clinical evaluation. Moreover, polypharmacological effects may increase antiviral activity and/or counteract severe complications concurrently affecting COVID-19 patients. Herein, we present the results of a computational drug repurposing campaign in search of potential inhibitors of the main protease of SARS-CoV-2. The screening allowed the selection of 22 promising drugs. Some of them have already entered clinical trials, but the vast majority of the identified compounds are new and have never been considered before. For each repurposed compound, its therapeutic relevance and potential beneficial polypharmacological effects that may arise due to its original therapeutic indication are thoroughly discussed.