The deal, brokered by the new agency , will promote the OSS in a bid to increase membership and raise awareness of its activities.
The campaign, also run by GallieGodfrey, begins on November 1 when details of 40 events are uploaded onto the swim map.
Potential new members or members organising their own events will be given the incentive of a special Zoggs swimming cap designed for the OSS and resembling a Christmas pudding.
It will also promote OSS partner Waterwise, with the message that even in winter we need to reduce the amount of water used.
Kate Rew, founder of the Outdoor Swimming Society, said: "We promote and encourage outdoor swimming all year round, but we wanted to do something particularly special this Christmas. GallieGodfrey have drawn up a strong campaign and brokered a great sponsorship deal with Zoggs which will help more swimmers than ever before enjoy a festive dip this winter."
Zoggs was founded in Australia in 1992 and makes items such as goggles, swimming costumes and caps.