Trail orienteering (TrailO) is an orienteering sport that involves precise reading of an orienteering map and the corresponding terrain. Trail orienteers must identify, in the terrain and in the presence of decoys, control points shown on the map. TrailO involves navigation skills but unlike most other forms of orienteering, it involves no point to point racing and little or no route choice. It is conducted usually on trails and because the objective is accuracy, not the speed of physical movement, the sport is accessible to physically disabled competitors on equal terms as able-bodied.
TrailO is one of four orienteering disciplines sanctioned by the International Orienteering Federation (IOF). European Championships in trail orienteering have been organised every year since 1994. The first ever World Cup in trail orienteering was held in 1999, and the inaugural World Trail Orienteering Championships were organised in 2004. The World Championships are now organised every year and were held in Vuokatti, Finland in 2013.