Flat Marathons in South East
Find flat marathons in South East in 2025/2026 - filter by date, location or category, display on a map or use the advanced search to find your perfect race.
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- Fri 26 Dec
- £33-£35
Boxing Day Challenge | Marathon
Come and join the day of running and aim to complete a marathon at your own pace on a flat, out-and-back route along the River Thames then receive a bespoke medal and goody bag at the finish!
- Enter online
- Flat
- Traffic free
- Age 18 & over
- 26.2 miles trail running + 0 ft ascent
- Sat 21 Feb 2026
- £53-£55
Magna Carta Winter | Marathon
The Magna Carta Marathon is based in scenic Runnymede right near the historic site where the treaty of Magna Carta was agreed by King John of England and signed on 15th June 1215.
- Chip timing
- Enter online
- Flat
- Traffic free
- Age 17-80
- 26.2 miles trail running + 150 ft ascent
- Sun 29 Mar 2026
- £33
Brett Lydd 20 Mile
A delectable racing experience perfect for those planning a spring marathon, over a pancake flat course using the wide, quiet country lanes surrounding the marsh town of Lydd in Kent.
- Chip timing
- Enter online
- Flat
- PB
- Age 18 & over
- 20 miles road running + 3 ft ascent
- Mon 4 May 2026
- £20-£27
Bank Holiday Madness May | Marathon
Come and join the day of running and aim to complete a midweek marathon within the 7-hour time limit on a scenic course then receive a fantastic medal and goody bag at the finish!
- Enter online
- Flat
- Traffic free
- Age 18 & over
- 26.2 miles trail running + 0 ft ascent
- Mon 4 May 2026
- £50-£60
MK Marathon
A multi award-winning marathon consistently ranked in the top 10 UK marathons with a stadium finish to give you goosebumps! AIMS-certified and BARR Gold accreditation for outstanding race management.
- Chip timing
- Enter online
- GPS tracking
- Flat
- PB
- Traffic free
- Relay
- Age 18 & over
- 26.2 miles road running + 938 ft ascent
- Sun 25 Oct 2026
- £37.50-£39.50
Wight Lines
Enjoy stunning coastal views on this flexible-distance run at Milford on Sea, following an out-and-back route beside Sturt Pond and the Isle of Wight — perfect for all abilities.
- Beginner-friendly
- Enter online
- Flat
- Event village
- Coast
- Public transport links
- Age 18 & over
- 7 hrs trail running + 47 ft ascent
- Sun 8 Nov 2026
- £26-£38
Remembrance Day Run | South | Marathon
Your chance to remember those who have given the ultimate sacrifice during conflicts around the world, with a two-minute silence, a marathon, then a Remembrance medal, a goody bag and a special pin.
- Enter online
- Flat
- Age 18 & over
- 26.2 miles trail running + 0 ft ascent
- Sun 21 Dec
Portsmouth Coastal Waterside Marathon Events | Portsmouth Coastal Waterside Marathon
- 26.2 miles multi terrain running
- Sun 28 Dec
Year End Marathon & Half Marathon | Marathon
- 26.2 miles trail running
- Sun 13 Sep 2026
The Garmin New Forest Marathon | Full Marathon
- 26.2 miles multi terrain running + 160 ft ascent