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

The Rosie Project is a 2013 Australian novel by Australian novelist Graeme Simsion. The novel centres on genetics professor Don Tillman, who struggles to have serious relationships with women. With a friend's help, he devises a questionnaire to assess the suitability of female partners. His plans are set off course when he meets Rosie, who does not fit many of Tillman's criteria, but becomes a big part of his life. The work was first published on 30 January 2013 in Australia by Text Publishing and the rights have since been sold in over 40 other countries. International sales are in excess of 3.5 million copies and the book was named Book of the Year for 2014 by the Australian Book Industry Association. In the United States the novel was published through Simon & Schuster and in the United Kingdom through Penguin Books.