Daniel O'Mahony (born 24 July 1973) is a half-British half-Irish author, born in Croydon. He is the oldest of five children, his siblings including Eoin O'Mahony of the band Hamfatter, and Madeleine O'Mahony, who has designed and made hats for Catherine, Duchess of Cambridge.
O'Mahony's first professionally published work were original Doctor Who novels in the 1990s. A fan of the series, when he was still at school he had pitched ideas to the BBC for episodes and also wrote to Nigel Robinson — the then editor of Target Books novelizations — asking to write the novelization of some of the few outstanding television stories yet to be adapted.
Following the announcement of Virgin's intention to start publishing the New Adventures, O'Mahony submitted a number of proposals for novels, the third of which (Falls the Shadow) was accepted and published in November 1994. This was the only book that O'Mahony wrote for the New Adventures. However, in July 1994 Virgin began publishing the Missing Adventures, and O'Mahony pitched a novel for this series and was accepted. The novel, The Man in the Velvet Mask was published in February 1996.
O'Mahony did not write any novels for BBC Books' Past Doctor Adventures and Eighth Doctor Adventures ranges. In fact since 1996 he has written only two traditional Doctor Who adventure stories, most prominently the Big Finish audio story Return to the Web Planet (2007). However, he also wrote the short story "Nothing at the End of the Lane" (in Short Trips and Side Steps in March 2000) and the 2003 novella The Cabinet of Light for Telos as part of their range of Doctor Who novellas. These are fabulations based around Doctor Who elements rather than Doctor Who stories proper, and feature the Doctor minimally if at all.