The 13.1 mile Semi de Paris takes you from the Bois de Vincennes park, along the Seine into the centre, on to Hotel de Ville and loops back around again. After 2025's sell out event, join Team Marsden and see what the buzz is all about!

Spectators line the Parisian streets to cheer you on with many musical events along the way. This beautiful course is relatively flat, allowing a significant number of runners to beat their personal bests.
Please note that for this event you will need to provide a medical certificate.
Registration
Training and fundraising support
Once you’ve signed up, you’ll receive one to one support from a dedicated member of the charity team to help you with your fundraising efforts and to answer any questions you may have as you prepare for the big day.
You’ll also have access to our professional half marathon training plans to encourage you to start logging those miles. Whether it’s your first big race or you’re a seasoned runner, our plans will help structure your training to make sure you are ready for the challenge.
When you register, you will also be able to join our Team Marsden Runners Facebook group. Our fun, friendly and supportive online community will be there to support you all the way, share top tips and advice and keep you motivated in the run up to the event.

Your registration includes:

Benjamin took on the Paris Half Marathon this year in the memory of his father Barrie who was a patient at The Royal Marsden.
"Sadly my father died in April 2026, one month after I completed the Paris Half Marathon. But thanks to the care from The Royal Marsden, he was able to undergo ground-breaking CAR-T cell therapy which prolonged his life and was able to spend an extra five years with us. The care he received really inspired me to get out and raise money so I can give something back and support the hospital and charity.
It was a brilliant course around Paris and the atmosphere is incredible. Although I was very nervous before starting, once I got into the groove it was so much fun. Crossing the finish line is a feeling unlike any other and knowing that every step I made was helping to raise money and make a real difference to so many people, helped me to make it to the end. It was great being part of the team and you feel like you are part of an elite team making a difference!"
Thanks to incredible supporters like Benjamin, we can we continue to be there for everyone who needs us!

We’d love to keep you up to date with inspiring stories, the latest breakthroughs, and ways you can make a difference.