Trail riding is riding outdoors on trails, bridle paths, and forest roads, but not on roads regularly used by motorised traffic. A trail ride can be of any length, including a long distance, multi-day trip. It originated with horse riding, and in North America, the equestrian form is usually called "trail riding", or, less often "hacking". In the UK and Europe, the practice is usually called horse, pony or donkey trekking.

The modern term also encompasses mountain biking, mixed terrain cycle touring, and the use of motorcycles and other motorized all-terrain vehicles. It may be informal activities of an individual or small group, or larger events organized by a club. Some equestrian trail rides in the USA are directed by professional guides or outfitters, particularly at guest ranches, while many equestrians who own horses trail ride on their own in local, state, and national trail systems. In some parts of the world, trail riding (of whatever kind) is limited by law to recognized, and sometimes function-specific, trails that are waymarked. in other towns, trails may be less maintained and more natural. Certain trails are limited by trail use types. Trail riding can be combined with other activities, such as camping, hunting, fishing, orienteering and backpacking.

Often, horses under saddle are subject to the same regulations as pedestrians or hikers where those requirements differ from those for cyclists. In most states, are not classified livestock and thus restricted from areas such as the right of way of the interstate highway system, though generally permitted to travel along the side of other roadways, especially in rural areas.

Rail trails, which are redeveloped disused railways converted into multi-use trails, often provide invaluable trail riding areas in many parts of the world. A bridle path, also called a bridleway, equestrian trail, horse riding path, bridle road, or horse trail, is a trail or a thoroughfare that is used by people riding on horses, though such trails often now serve a wider range of users, including equestrians, hikers, and cyclists. Such paths are either impassable for motorized vehicles, or vehicles are banned. The laws relating to allowable uses vary from country to country.

In England and Wales a bridle path now refers to a route which can be legally used by horse riders in addition to walkers, and since 1968, by cyclists but not motor-cyclists. In the US, the term bridle path is used colloquially for trails or paths used primarily for people making day treks on horses, and used primarily on the east coast, whereas out west the equivalent term is simply trail. The United States has few if any formal designations for bridle paths, though horses are generally allowed on most state and federal trails, roads and public routes except where specifically restricted, although rules differ among locations.

There is some criticism of trail riding when excess or improper use of trails may lead to erosion, the spread of invasive plants, conflict with hikers, or harassment of wildlife. Off-road or trail activity is usually not permitted, as such activity may also raise the risk of soil erosion, spread weeds, and cause other damage. However, many responsible equestrians, mountain bikers, and off-road motorcyclists, especially those who get involved in these sports by joining an organized club, perform hours of trail maintenance every year. Many organizations also sponsor educational events to teach newcomers about safety, responsible land stewardship and how to improve riding techniques.

Many long-distance trails throughout the world have sections suitable for horse riding, some suitable throughout their length, and some have been developed primarily for horse riding. Within the United States National Trail Classification System, equestrian trails include simple day-use bridle paths and others built to accommodate long strings of pack animals on journeys lasting many days. Some trails managed by the U. S. Forest Service and other governmental entities may restrict access of horses, or restrict access during certain times of the year. Access to trails and pathways on private land is generally left to the discretion of the landowner, subject to the general trespass laws of each of the 50 states.

The term pleasure riding may encompass trail riding. This refers to a form of equestrianism that encompasses many forms of recreational riding for personal enjoyment, without any element of competition. Pleasure riding is called "hacking" in United Kingdom, and in parts of the eastern United States and Canada. In other parts of the United States, particularly the Western United States, the term trail riding is used interchangeably with pleasure riding when on natural trails or public lands. African American communities in some rural parts of the Southern United States and South Central United States have a tradition of Black trail rides that often involve music, dancing, and shared meals along with horse riding.