But instead of giving gifts, the santas will be taking donations – for Variety, the children's charity.

The fun run will be held Sunday, and starts at 8.30am from Westside Acton Park.

Variety focuses on children who fall through cracks in the system, providing equipment, grants and medical assistance.

Last year the charity helped over 27,000 children in the ACT and NSW.

Five times Paralympian Richard Nicholson is this year's Canberra ambassador and says he hopes people will get into the giving spirit this weekend.

"Hopefully we get a thousand santas this year and raise $20,000," he said.

The cause is close to his heart, as sport played such an important role in his childhood.

"It was difficult accessing sport back then," said Mr Nicholson.

"It's improved significantly, and clubs are a lot more inclusive of people with disabilities than they used to be, but there's still a lot of work to be done."

It's situations like these where Variety steps in to donate equipment, education and experience for struggling children.

The charity focuses on helping children who are sick, disadvantaged or are special needs, said Variety ACT and NSW chief executive Pam Johnston.

"Our aim is to help kids live, laugh and learn," she said.

"Variety's job is about helping connect communities to families … we look for the unmet needs."

Ms Johnston said the santa fun run was starting to become a feature in the Canberra landscape.

"You know Christmas is coming when you see all those santas going around the lake," she said.

For those concerned they might heat up in the suits, Ms Johnston said Variety provides a light weight cotton santa suit.

"They're actually shorts instead of pants – but I guess once you put the beard on it might get a bit warm," she said.

"But come on down to watch the sea of santas run around the lake.

"It's really exciting, it's for a good cause, and it's a great way to herald in Christmas."

Donations can be given to any santa, to Variety itself, or individually on registration for the fun run.

For more information, visit varietysantafunrun.com.au.