Siobhan Dowd (4 February 1960 – 21 August 2007) was a British writer and activist.

She was born to Irish parents and brought up in London, spending much of her youth visiting family homes in County Waterford and later in Wicklow Town. Dowd attended a Catholic grammar school in south London before obtaining a degree in Classics from Lady Margaret Hall, Oxford University, followed by an MA with distinction in Gender and Ethnic Studies from Greenwich University.

In 1984, she joined International PEN, becoming Program Director of the PEN American Center’s Freedom-to-Write Committee in New York City. Her notable work included founding and leading the Rushdie Defense Committee USA and traveling to Indonesia and Guatemala to investigate human rights conditions for writers. During her time in New York, she was recognized as one of the ‘top 100 Irish-Americans’ by Irish-America Magazine and Aer Lingus for her global anti-censorship work.

Upon returning to the UK, she co-founded English PEN’s readers and writers program, which engages authors in socially deprived areas, prisons, and community projects. In 2004, she served as Deputy Commissioner for Children’s Rights in Oxfordshire, promoting children’s rights in accordance with UN protocols.

Dowd edited two anthologies in the Threatened Literature Series: This Prison Where I Live: The PEN Anthology of Imprisoned Writers (1996) and, with Ian Hancock and Rajko Djuric, The Roads of the Roma: A PEN Anthology of Gypsy Writers (1998 and 2004). Her literary career was catalyzed by contributing a story to Tony Bradman's Skin Deep (2004), leading her to become a successful children's author. Her last completed book, Bog Child, posthumously won the 2009 Carnegie Medal.

Siobhan Dowd died in August 2007 at the age of 47. In her final days, she established the Siobhan Dowd Trust, continuing her lifelong dedication to charitable and literary causes.