Jo Mazelis is the author of short stories, non-fiction and poetry. Her collection of stories, Diving Girls (Parthian, 2002), was short-listed for the Commonwealth 'Best First Book' and Wales Book of the Year. Her second book, Circle Games (Parthian, 2005), was long-listed for Wales Book of the Year. Her stories and poetry have been broadcast on BBC Radio 4 and published in various anthologies and magazines, and translated into Danish. Her novel Significance (Seren, 2014) was the 2015 Jerwood Fiction Uncovered Prize-winner.

Born and educated in Swansea Jo returned to her home town in 1991 after working in London for many years. During the 1980s she worked as a graphic designer, photographer and illustrator for the magazines City Limits, Women's Review, Spare Rib, Undercurrents, Everywoman and New Dance.