Ward originally wanted to become an actress. She first appeared at the age of 10 she appeared on the stage of school drama. The model Ward ended up accidentally. She was discovered in 2002 when she was with her friends in the Australian Model Contest. Eventually, she was chosen to race, but she did not win. However, her fragile and unique look was brought to attention by Vivien's Model Agence, who made him a model folder.
At age 15, Ward had already conquered the Australian Fashion Week and came to Italy to meet Miuccia Prada. Soon after she was on the cover of Australian magazine Mark and a seat on the catwalk Week Fashion of Australia, sponsored by Mercedes-Benz. The photos of Mark magazine came to an IMG agent. In 2003, she signed with the IMG agency and in September, she made her debut on the catwalk for the spring collection of Prada in Milan, as an exclusive. In January 2004, she became the showstopper for Valentino spring collection in Paris. She became the face for the campaigns of Jil Sander, Yves Saint Laurent, and was photographed by Steven Meisel for Prada.
In 2005, she participated in John Mayer's music video of the song "Daughters”. She was highlighted on the cover of the French magazine Vogue, February edition, Vogue Italy, April edition, and in the inaugural edition of Vogue China in September. In October of 2006 in the magazine Allure, Ward was described as "the model of the moment". Creative Director of Allure, Paul Cavaco said: "We went through a period that was very va-va-Voom, but now the pendulum has come back, Gemma is ethereal, not earthly." Photographer Michael Thompson says, "She is an exotic blonde, the rarest of creatures."$ 25,000 to walk on the catwalks. In 2009, news that Ward left the modelling world due to foul attacks on her weight. But the model associated the time stopped, after the unfortunate death of Ledger, to the need to address particular issues and find out what she wanted out of life.
Her journey in cinema began when in 2001 she played the role of "Heidi" in Pink Pajamas. On the side of Rhys Wakefield and Toni Collette, Ward plays in the movie The Black Balloon, which had its world premiere at the 2008 Berlinale and won the Glass Bear in Generation 14 plus section. In the horror film The Strangers (2008) she starred alongside Liv Tyler and Scott Speedman, but her face is masked by a mask throughout the movie, except for a short scene earlier. 2011 she is in Pirates of the Caribbean - Seeing foreign tides as a mermaid. In the remake of The Great Gatsby (2013), Gemma Ward has the second appearance.