The Israeli actress and former Miss Israel posted: "Israel deserves to live as a free and safe nation," adding: "Our neighbours deserve the same."
The comments attracted thousands of replies - now switched off - leading to her name trending on Twitter.
In her youth, Gadot completed two years of mandatory military service.
"My heart breaks," the 36-year-old posted online.
"My country is at war. I worry for my family, my friends. I worry for my people. This is a vicious cycle that has been going on for far too long.