counterprotestor

From counter- +‎ protestor.

counterprotestor (plural counterprotestors)

1. One who counterprotests.
   • 2025 January 15, Linda Feldmann, “Outside the DC jail, where Jan. 6 rage and devotion live on”, in The Christian Science Monitor:

     Counterprotesters shouted epithets as they walked by, but the opposing groups kept it nonviolent.