More than 40 crazy soapbox cars will race through The Quarry Park on May 26.
It has also been announced the Andy Ash, the fastest gravity racer in Europe who set the record at 91.92MPH in 2017, will be the scrutineer and soapbox safety expert for the event.
Event organiser Sarah Belcher from Sarah Belcher Events Limited said: “We are so very lucky to be working with Andy Ash on the event and he will bring a professionalism and expertise in Soapbox racing to the event. We are also very please to be working with Macmillan charity as it is such a worthwhile cause."
The charity has now put out a call to townspeople to become volunteers on the day.
Sarah added: "We can’t thank Macmillan enough for their help with recruiting volunteers and we are certainly looking forward to their trademark cake stalls. We are gearing up for this to be a stand-out event in Shrewsbury’s event calendar next year, one which we hope local residents and visitors will enjoy and grow each year."
Macmillan is the UK’s leading cancer support charity, giving personal, one to one care and support to thousands of people every day.
Kate Thomas fundraising manager Shropshire said the Soapbox Derby was the ideal opportunity to work together with the events team to raise awareness of the charity and raise vital funds.
She added: "We are delighted to be the chosen charity for Shrewsbury Wacky Races 2019. We are working alongside the events team to recruit volunteers and planning lots of fundraising ideas to form part of the fun filled day! Fundraising is hugely important to Macmillan. Without people doing events, running marathons, climbing mountains, and donating, Macmillan wouldn’t exist and we are over the moon to be involved in event such as Shrewsbury Wacky Races."
If you would like to volunteer on the day for Shrewsbury Wacky Races go to volunteering.macmillan.org.uk/Opportunity/Details/6233