Polygon is a bicycle brand founded in 1989 in Sidoarjo, Indonesia, and is the house brand of manufacturer PT Insera Sena. It makes a full range of bikes across road, urban and off-road, but is best known for its mountain bikes — from the Siskiu trail range to the Collosus and Xquarone gravity models.

Polygon co-developed the R3ACT suspension system with US engineer Darrell Voss, and sells internationally through both distributors and direct online channels. It has long supported gravity racing through the Polygon UR team.