Silver Shell for Best Supporting Performance

The Silver Shell for Best Supporting Performance (Spanish: Concha de plata a la mejor interpretación de reparto; Basque: Taldeko interpretazio onenaren zilarrezko maskorra) is one of the main awards presented at the San Sebastián International Film Festival to the Best Supporting Performance of a competing film. In 2021, the San Sebastián International Film Festival announced that the two acting categories would be retired and replaced with one gender neutral category, with both Best Actor and Best Actress merging into the Best Leading Performance and Best Supporting Performance category.