Cross Country running is a sport in which teams of runners compete to complete a course over open or rough terrain faster than other teams. The courses used at these events may include grass, mud, woodlands, and water. It is a popular participatory sport, and usually takes place in temperate regions during the autumn and winter when soft conditions underfoot prevail.

Each cross-country running course is different in composition. Distances are generally standardized, however there will be little in common between any two courses other than their distance. As such, accurate comparisons cannot be made between performances on different courses or even on the same course on different years as the weather and underfoot conditions can be significantly different. For this reason, records of the fastest times in international competition are not kept.