Graeme C. Simsion is a New Zealand-born Australian author, screenwriter, playwright, and data modeller, best known for his first novel The Rosie Project.

[1] Prior to becoming an author, Simsion was an information systems consultant, co-authoring the book Data Modelling Essentials, and worked in wine distribution.

[2][3] In 2012 Simsion won the Victorian Premier's Unpublished Manuscript Award for his book The Rosie Project.

[7][8] Simsion initially wrote The Rosie Project as a screenplay, which has since been optioned to Sony Pictures Entertainment.

[11] Simsion's fourth novel Two Steps Forward, a collaboration with his wife Anne Buist, was published on 2 October 2017.