Marthe Jocelyn (born 1956)^[1] is a Canadian writer of over forty children's books.^[2][3] In 2009, she received the Vicky Metcalf Award for Literature for Young People, an honour bestowed by the Writers' Trust of Canada to a writer or illustrator whose body of work has been "inspirational to Canadian youth".^[4][5]

Jocelyn was born in 1956 in Toronto and was raised in Stratford, Ontario.^[1] As a teenager, she attended a boarding school in Great Britain. After living in various areas, she settled in New York City,^[1] where she lived for thirty years before returning to Stratford.^[6]

She is married to Tom Slaughter and has two daughters: Hannah and Nell.^[1] Tom and Nell have contributed illustrations to a number of her children's books.

Aside from writing, Jocelyn owned Jesse Design, a "toy and clothing design firm", for fifteen years.^[1]

In 2009, Jocelyn received the Vicky Metcalf Award for Literature for Young People,^[5][7] an honour bestowed by the Writers' Trust of Canada to a writer or illustrator whose body of work has been "inspirational to Canadian youth".^[4]

Five of Jocelyn's books are Junior Library Guild selections: Earthly Astonishments (2000),^[8] Mable Riley (2004),^[9] Folly (2010),^[10] The Body under the Piano (2020),^[11] and Peril at Owl Park (2021).^[12] Two of her books have been included on USBBY's Outstanding International Books List: Would You (2009)^[13] and Sam Sorts (2018).^[14]

In 2007, the Toronto Public Library included Eats on their "list of the top 10 books of 2007 for children under the age of five".^[15] The same year, School Library Journal named How It Happened in Peach Hill one of the best children's books of the year.^[16]

Folly was named one of the Kirkus Reviews' best books for teens in 2010, and Bank Street College of Education included it on their 2011 list of the best Historical Fiction for Children Ages 14+.^[10]

• Earthly Astonishments (2000)
• Hannah's Collections (2000)
• A Day with Nellie (2002)
• Mable Riley: A Reliable Record of Humdrum, Peril, and Romance (2004)
• One Some Many, illustrated by Tom Slaughter (2004)
• Over Under, illustrated by Tom Slaughter (2005)
• ABC x 3, illustrated by Tom Slaughter (2005)
• How It Happened in Peach Hill (2007)
• Eats, illustrated by Tom Slaughter (2007)
• Ready for Summer (2008)
• Would You (2008)
• Same Same, illustrated by Tom Slaughter (2009)
• Folly (2010)
• Scribbling Women (2011)
• Ones and Twos, illustrated by Nell Jocelyn (2011)
• What We Hide (2014)
• Viminy Crowe's Comic Book, with Richard Scrimger, illustrated by Claudia Dávila (2014)

The Aggie Morton books are illustrated by Isabelle Follath.

• The Body Under the Piano (2020)
• Peril at Owl Park (2020)
• The Dead Man in the Garden (2021)
• The Seaside Corpse (2022)