The Pennine Way is a National Trail in England, with a small section in Scotland. The trail stretches for 268 miles (431 km) from Edale, in the northern Derbyshire Peak District, north through the Yorkshire Dales and Northumberland National Park and ends at Kirk Yetholm, just inside the Scottish border. The path runs along the Pennine hills, sometimes described as the "backbone of England". Although not the United Kingdom's longest National Trail, it is, according to The Ramblers, "one of Britain's best known and toughest".

The path was the idea of the journalist and rambler Tom Stephenson, inspired by similar trails in the United States, particularly the Appalachian Trail. Stephenson proposed the concept in an article for the Daily Herald in 1935, and lobbied Parliament for the creation of an official trail. The walk was planned to end at Wooler but it was decided that Kirk Yetholm would be the finishing point. The final section was declared open in a ceremony held on Malham Moor on 24 April 1965. Before the official opening of the Pennine Way the British Army was invited to test the route, a task that was accomplished in one day. Junior soldiers from the Junior Tradesman's Regiment of the Army Catering Corps, based in Aldershot, were split into patrols of four or five and each was allocated an approximately 15-mile (25 km) section of the walk. A report was then provided on the signage and route feasibility.

The Pennine Way celebrated its 50th anniversary in April 2015. A special four-part BBC One series The Pennine Way was broadcast throughout April.

The Pennine Way is popular with walkers, and in 1990 the Countryside Commission reported that 12,000 long-distance walkers and 250,000 day-walkers were using all or part of the trail annually and that walkers contributed £2 million (1990) to the local economy along the route, directly maintaining 156 jobs. The popularity of the walk has resulted in substantial erosion to the terrain in places, and steps have been taken to recover its condition, including diverting sections of the path onto firmer ground, and laying flagstones or duckboards in softer areas. The actions have been effective in reducing the extent of broken ground, though the intrusion into the natural landscape has at times been controversial.

Accommodation is available at youth hostels, camp sites, bed-and-breakfasts and pubs, but is limited on upland stretches, so when planning the walk one must sometimes choose between a long day (between two places offering on-route accommodation) or two shorter days involving an evening descent off-route (to a nearby village or farm) with a morning re-ascent.

There are 535 access points where the Pennine Way intersects with other public rights of way. The route is crossed by many roads and passes through many villages and towns with good public transport. This makes it easy to sample a short section of the trail, or to split the Pennine Way across several holidays or long weekends.

Most of the Pennine Way is on public footpaths, rather than bridleways, and not accessible to travellers on horseback or bicycle, but a roughly parallel Pennine Bridleway is open from Derbyshire to Cumbria. This route, open to anyone not using motorised vehicles, starts slightly farther south than the Pennine Way.

A survey by the National Trails agency reported that a walker covering the entire length of the trail is obliged to navigate 287 gates, 249 timber stiles, 183 stone stiles and 204 bridges. 198 miles (319 km) of the route is on public footpaths, 70 miles (112 km) on public bridleways and 20 miles (32 km) on other public highways. The walker is aided by the provision of 458 waymarks.