Gemma Ward was born in Perth, Western Australia, as the second child of Gary and Claire Ward. Her older sister, Sophie, is also a model and she has younger twin brothers, Oscar and Henry Ward. She was discovered in 2002 when she was in the Australian television show Search for a Supermodel, which she was persuaded to enter. Although not making it past the early rounds, the eventual winner being fellow Perth model Nicole Trunfio, her unique look and mesmerizing face hadn't gone unnoticed. This was just the beginning of an international supermodel in the making. She was signed by Vivien's Model Management based in Australia and IMG in New York. She is a former student of Presbyterian Ladies' College, Perth and Shenton College.

At only sixteen, Ward was the youngest model to be listed by American Vogue as one of the nine "It Girls" in the modeling world, which also included Daria Werbowy, Gisele Bundchen and Karolina Kurkova. Ward has been on campaigns from Prada to Yves Saint Laurent and been in shows for designers such as Versace, Gucci, Chanel, Valentino, Alexander McQueen, and many more. She has also graced magazine covers such as Vogue, W, and TIME Magazine's Style and Design issue. In September 2004, at the age of sixteen, Ward became the youngest fashion model on the cover of the American edition of Vogue and was the first model to appear on the cover of Teen Vogue magazine. She is the first model since Kate Moss to be the face for Calvin Klein's perfume Obsession Night for Men along with male model Drew Keilt.

To date Ward's clients have included Balenciaga, Burberry, Calvin Klein, Christian Dior, Dolce & Gabbana, Hermes, Jean-Paul Gaultier, Jil Sander, Karl Lagerfeld, Louis Vuitton, Prada, Swarovski, Valentino and Yves Saint-Laurent, and, altogether, Ward has appeared on 24 covers of Vogue magazine worldwide.

Ward is currently being considered a model of the moment by many fashion insiders and fans alike, having been described at times of having an out-of-this-world look. British photographer Nick Knight stated, "Gemma is one of the very, very few models who look as though they come from another dimension." She currently lives in New York and is close friends with fellow models Lily Donaldson, Caroline Winberg, Daria Werbowy, and Lily Cole. Marissa Johnson, heiress to Johnson & Johnson fortune and Ward have been friends since Ward entered the modeling industry, they are both some of the highest paid young models in the industry.

Ward's baby doll-like look inspired a new craze in fashion. Fashion designer Lazaro Hernandez of Proenza Schouler told Teen Vogue in February 2006 that," She looked like no one else at the time. She was this alien, and fashion is always looking for newness." Her look became the popular new look among models. It has inspired a new generation of baby doll-like models such as Vlada Roslyakova, Heather Marks, and Jessica Stam.

In Allure magazine October 2006, Ward is described as "the model of the moment." Allure's creative director Paul Cavaco knows why: "We went through a period that was very va-va-voom, but now the pendulum has swung back. Gemma is ethereal, not earthy." Photographer Michael Thompson says, "She's an exotic blonde, the rarest of creatures."

Ward has long aspired to pursue acting and drama is a passion that she has held since she was a child. She starred as Heidi in the 2001 short film Pink Pyjamas, directed by Australian Elissa Down and also her upcoming film The Black Balloon, as Jackie, the girlfriend of a boy whose brother has autism. She was recently cast opposite Liv Tyler in the suspense thriller The Strangers as one of the three masked intruders. She also starred in John Mayer's music video for Daughters.

Ward is set to appear on the cover of the first issue of Vogue India; photographed by famed photography Patrick Demarchelier. This is the second time Ward has appeared on an inaugural issue - the first time being the first-ever cover of Vogue China in 2005.

In July 2007, earning at an estimated total of $3 million in the past 12 months, Forbes named her tenth in the list of the World's 15 Top-Earning Supermodels after Daria Werbowy, Karolina Kurkova, Natalia Vodianova, Carolyn Murphy, Alessandra Ambrosio, Adriana Lima, Heidi Klum, Kate Moss,and Gisele Bundchen.