Trail Running Calendar South East (England) 2025-2026

Henley River Half Marathon, 10K & Junior Race, organized by RunThrough UK, takes place at Temple Island Meadows, Remenham Lane, Henley-on-Thames. The event offers three distances—the Half Marathon, 10K, and a Junior Race—on a scenic, mixed-terrain course along the River Thames. The route is undulati..

Spring ‘Run the Seasons’ Cowdray takes place on the Cowdray Estate in West Sussex, near Midhurst. The event offers 5km, 10km, 10-mile and canicross options, all run on a scenic course that heads out to Ambersham and Heyshott Common. These commons are Sites of Special Scientific Interest and Grade 2..

Centurion Running’s 50 Mile Grand Slam 2026 is a four-race ultramarathon series, consisting of four 50-mile events on famed UK trails: South Downs Way 50 (11 Apr), North Downs Way 50 (16 May), Chiltern Wonderland 50 (19 Sep), and Wendover Woods 50 (14 Nov). The four races are grouped as All Four 202..

The Spring Trail Series by Ultra X is a trail running event held at the Cowdray Estate in Surrey, within the scenic South Downs National Park. The series features five race distances: 12km, 25km, 50km, 50 miler, and 110km, all set along the picturesque Serpent Trail that traverses greensand hills, r..

Windsor 50 Ultra Challenge, formerly The Easter 50, is staged from Windsor Racecourse and offers 50 km, 25 km, or 10 km loop options. Participants traverse looped routes from the basecamp through Windsor Great Park with castle views, to Runnymede and along the Thames Path into surrounding countrysid..

Chiltern Ridge Classic 50K is Runaway Racing’s iconic ultra through the Chiltern Hills. The next edition, 18 April 2026, runs from Berkhamsted Castle to Hampden Meadow, Wendover, covering roughly 51 km with about 996 m of ascent. Runners traverse the Ridgeway National Trail, with an undulating first..

The Ale Trail 15 mile run is a pub-led trail race in Alfriston, East Sussex, starting from the Ye Olde Smugglers Inne beer garden. The 15-mile course has a 4hr30min cut-off and pub checkpoints at The Hampden Arms and The Ram Inn, where runners log arrival and receive a beer token and snacks before c..

The Drop - Winchester is a unique and challenging race held in Winchester, UK, offering participants a choice between 10-mile and 15-mile distances, either solo or in teams. Inspired by military-style navigation, the event requires runners to find their way back to the event center from an undisclos..

Greensand Way Ultra Run is a 30-mile trail ultramarathon starting and finishing at West Hanger, Staple Lane Car Park, near Guildford in Surrey. The route links the North Downs Way with the Greensand Way, passing Box Hill, Leith Hill (the South East’s highest point) and summits such as Pitch Hill and..

Rapid Relays is a dynamic running event held at the scenic Culden Faw Estate in Fawley, near Henley on Thames, Oxfordshire. The race features a woodland trail course on estate tracks with gently undulating terrain, including a notable climb before 3 kilometers followed by a long downhill stretch bac..

Three Forts Challenge is a trail-running event based at Lancing Manor Leisure Centre in West Sussex. It offers three races: a Full Marathon (27.2 miles) starting and finishing at Lancing Manor, with steep climbs, stiles and rough tracks, passing Chanctonbury Ring and Cissbury Ring for panoramic coun..

Box Hill Vertical KM is a guided trail run held around Box Hill near Dorking, Surrey. The course covers about 12.5 miles with around 1000m of elevation, designed to rack up significant height in a compact distance. It traverses woodland, heathland and open fields, with hills that are technical enoug..

BigWayRound - Winchester is an award-winning, Gold-rated trail running event held at Winchester Rugby Club. The event offers four distances: 14 miles, 19 miles, a marathon, and a 50K ultramarathon, catering to both new and experienced trail runners. The course features stunning views and traverses i..

The Harewood Forest Trail Race is staged in Harewood Forest in the heart of the Test Valley, near Andover, Hampshire. Runners can choose between 5k and 10k trail routes on undulating forest tracks, offering a challenging yet scenic course. Described as a spring race set in a beautiful woodland setti..

The Goring Gap Trails event, held in Mapledurham near Reading, offers a variety of running and walking challenges, including a 50-mile ultra, a 52K ultra, and a half marathon, alongside walking options of half marathon, full marathon, and a 6-mile walk featuring a river boat crossing. The event is l..

The Chiltern Hills 100K is a 100-kilometer ultra marathon held in the Chiltern Hills, Buckinghamshire, UK. The race features an anticlockwise loop starting and finishing in Chesham, passing iconic landmarks such as Ashridge Estate, Coombe Hill, Whiteleaf Hill, Bledlow Ridge, and Great Hampden. With..

Run to the Sea Brighton is a 50 km point-to-point ultramarathon from Christ's Hospital School in Horsham to Hove Lawns on the Brighton seafront. The multi-terrain course features trails, rolling downs and a coastal promenade, offering scenic views and a reputation for superb organisation and a frien..

The Oliver Fisher 10k & 5k is an annual running event held at Milton Creek Country Park in Sittingbourne, Kent. Featuring off-road stone trail courses, the race offers 10k and 5k distances along with a junior run, making it suitable for runners of all ages and abilities. The scenic route showcases t..

North Downs Way 50 is a 50-mile point-to-point ultramarathon hosted by Centurion Running, running along the North Downs Way National Trail from Farnham, Surrey to Knockholt Pound near Greater London. The route features about 5,600 feet (1,700 m) of ascent and reflects the first 50 miles of the NDW10..

The Reigate Priory Park 10K is a scenic charity fun run held in Priory Park, Reigate, Surrey. The course features a 250-meter start plus four laps on an accurately measured, gently undulating cross-country terrain surrounded by lush greenery. Suitable for runners of all levels, the event fosters a f..