Tangible Response will lead on strategy and creative development, while Irish firm DirectBrand will focus on digital delivery, such as email campaigns, and manage accounts locally.
The Irish Cancer Society has signed a deal to develop a five-year campaign with the partnership, including direct mail, television and digital campaigns.
Stephen Pidgeon, chair of Tangible Response, said Ireland was about 15 years behind the UK. "Direct marketing is relatively underdeveloped and not near to threatening consumer trust and patience," he said.
"Irish people tend to be responsive and innately generous. As far as charity support is concerned, they simply haven't been asked properly."