Simon Guerrier is a British science fiction author and dramatist, closely associated with the fictional universe of Doctor Who and its spinoffs. Although he has written three Doctor Who novels, for the BBC Books range, his work has mostly been for Big Finish Productions audio drama and book ranges.

Guerriers earliest published fiction appeared in Zodiac, the first of Big Finishs Short Trips range of Doctor Who short story anthologies. To date, his work has appeared in the majority of the Short Trips collections. He has also edited three volumes in the series, The History of Christmas, Time Signature and How The Doctor Changed My Life. The second of these takes as its starting-point Guerriers short story An Overture Too Early in The Muses. The third anthology featured stories entirely by previously unpublished writers.

After contributing two stories to the anthology Life During Wartime in Big Finishs Bernice Summerfield range of books and audio dramas, Guerrier was invited to edit the subsequent years short story collection, A Life Worth Living, and the novella collection Parallel Lives. After contributing two audio dramas to the series, Guerrier became the producer of the Bernice Summerfield range of plays and books, a post he held between January 2006 and June 2007.

His other Doctor Who work includes the audio dramas, The Settling and The Judgement of Isskar, in Big Finishs Doctor Who audio range, three Companion Chronicles and a contribution to the UNIT spinoff series. He has also written a play in Big Finishs Sapphire and Steel range.

Guerriers work is characterised by character-driven humour and by an interest in unifying the continuity of the various Big Finish ranges through multiple references and reappearances of characters. As editor he has been a strong promoter of the work of various script writers from the Seventh Doctor era of the Doctor Who television series