The new assignment will see Iris handle the strategy, advertising, PR, experiential and digital marketing.
Iris will develop an integrated campaign targeted at women in their 20s and 30s. The new campaign is expected to launch in the UK later this year, followed by a European roll-out.
Iris has worked in the UK with Wonderbra on PR campaigns since 2005 and this new appointment sees the two organisations extend their relationship into creative strategy. Publicis remains Wonderbra's retained agency.
Last year, Iris launched a PR campaign to support the launch of Wonderbra's new D-G cup size range which involved a nationwide search for more than 1,000 women to appear in a billboard campaign.