Swimmers will brave the waters at Pugneys Country Park to raise money for charity.
The Jane Tomlinson Yorkshire Swimming Festival will see hundreds of people make a splash on Sunday.
And for the first time the third annual Express-backed event will include an Aquathlon made up of a 1k swim and 5k run.
Other races will include the 500m or 1,500m open water swims for different age groups from 12 years old.
More than 300 athletes have signed up from across the UK for the event, which is organised by Jane Tomlinson’s Swim For All charity.
It was set up as a lasting legacy to the inspirational fundraiser and campaigner who raised £1.85m for children’s and cancer charities before she died from cancer aged 43 in 2007.
The event has been backed by Olympian Sharron Davies, who first swam for Great Britain at the age of 11.
She said: “Jane Tomlinson was an incredible inspiration, whether she was running, walking or swimming. The festival is a great event for all abilities and this year’s Aquathlon will be an extra challenge.”
There will be a 500m junior wave for youngsters aged between 12 and 17, a 500m adult wave or a tougher 1,500m wave, as well as the Aquathlon.
The first swim will start at 9am.
Funds from the event will go towards Forget Me Not Children’s Hospice, Leeds Children’s Hospital Appeal, Bluebell Wood Children’s Hospice, Sheffield Hospitals Charity, Macmillan Cancer Support, Yorkshire Cancer Research and the Jane Tomlinson Appeal.
For more details visit www.swimforall.co.uk