The 24-year-old beat out Liam Hemsworth and rocker Daniel Johns to be crowned PETA's meat-free maven, reported Daily Telegraph.
She succeeds actress Isabelle Cornish, who was last year's
hottest vegan.
"At the rate of heart disease, cancer and diabetes, I don't understand how people can be OK - and even proud - of their bad eating habits when they are killing themselves slowly," Malcolm said in a statement issued by PETA.
"It physically pains me to see suffering, and I go out of my way to avoid any chance of hurting another creature - human, animal or insect. Not to mention how animal agriculture is the biggest destroyer of our natural world.