Diffusion: Cardiff International Festival of Photography is a biennial month-long international festival of photography taking place in Cardiff, Wales' capital city. The festival is initiated and delivered by Ffotogallery in collaboration with a wide range of local, national and international partners and supporters.

Diffusion is a celebration of photography and the photographic image, in all its forms. Whether created, published, exhibited, collected or distributed in a physical or virtual way, the photograph has the power to inspire and provoke reaction, to reflect our own experience and that of society evolving around us.

After highly successful Diffusion festivals in 2013 and 2015, 2017 will be the third edition of the festival.