About the event

Unfortunately Children with Cancer UK Swim Serpentine was not able go ahead in 2020 due to COVID-19, but we are delighted to let you know that the date for 2021 has been announced, Saturday 18th September 2021.

Swim Serpentine, organised by London Marathon Events Ltd, is the biggest open water swimming event in the country. It has rapidly grown to become the UK’s top open water swimming event with more than 6,000 entries in 2019!

We’re thrilled to partner with London Marathon Events and bring you Children with Cancer UK Swim Serpentine. The day will feature open water swimming events in the Serpentine Lake in Hyde Park over a range of distances, including ½ mile, one mile, two miles and six miles.

Join Children with Cancer UK and swim the Serpentine to fund vital research into the prevention and treatment of childhood cancer.

Children with Cancer UK have charity places available in the 2 mile distance only. To Join the Children with Cancer UK and swim 2 miles to fund vital research into the prevention and treatment of childhood cancer, see below how you can be part of our 2021 team.

What to expect from Children with Cancer UK

We will ensure that we get you to the finish line. We’ve got training and fundraising advice, cheering packs for your friends and family, and a dedicated team ready to answer any last minute questions.

You can be part of our team whether you secure your own place independently of the charity or are allocated one of our charity places. When you join our team, you will receive the following support from us;

  • Fundraising Pack containing lots of fundraising advice
  • Regular emails providing top tips and information about Swim Serpentine event
  • Access to our open water swimming training plans
  • A Children with Cancer UK T-Shirt
  • The best support and loudest cheers on the day

Location & Date

  • Hyde Park, London
  • September 18, 2021

View map

Contact Details


Join our team

Charity Place

If you’d like to join our team as a charity place swimmer, please complete the form below. Charity places are available in the 2 mile distance only.

Registration fee: £20

Fundraising target: £200

Own Place

If you have secured your own place through the race organisers and would like to join our team, please complete the form below.

Registration fee: £0

Fundraising target: as much as possible

Registration forms

If you’d like to join our team as a charity place swimmer, please complete the form below. Charity places are available in the 2 mile distance only.

Registration fee: £20

Fundraising target: £200

Charity Place - Swim Serpentine 2021 SWIM21

Step 1 of 2

  • Price: £ 20.00
  • Please enter a number less than or equal to 1.
  • £ 0.00

If you have secured your own place through the race organisers and would like to join our team, please complete the form below.

Registration fee: £0

Fundraising target: as much as possible

Own Place - Swim Serpentine 2021 SWIM21

  • Price: £ 0.00
  • Please enter a number less than or equal to 5.
  • £ 0.00
  • Date Format: DD slash MM slash YYYY
  • I am happy to be contacted by Children with Cancer UK regarding their challenge events, including Swim Serpentine, as well as their charitable work. Please contact me by:
  • Hidden Fields

    Don't edit these

If you’d like to join our team as a charity place swimmer, please complete the form below. Charity places are available in the 2 mile distance only.

Registration fee: £20

Fundraising target: £200

Charity Place - Swim Serpentine 2021 SWIM21

Step 1 of 2

  • Price: £ 20.00
  • Please enter a number less than or equal to 1.
  • £ 0.00

If you have secured your own place through the race organisers and would like to join our team, please complete the form below.

Registration fee: £0

Fundraising target: as much as possible

Own Place - Swim Serpentine 2021 SWIM21

  • Price: £ 0.00
  • Please enter a number less than or equal to 5.
  • £ 0.00
  • Date Format: DD slash MM slash YYYY
  • I am happy to be contacted by Children with Cancer UK regarding their challenge events, including Swim Serpentine, as well as their charitable work. Please contact me by:
  • Hidden Fields

    Don't edit these