Hollywood was stunned in November when it emerged the actor had been killed in a horrific car smash in California aged 40.
Now Alba, who teamed up with Walker on their 2005 sea disaster movie, has spoken out to pay tribute to the down-to-earth star, reported Marie Claire magazine.
"He had a real childlike innocence and he was game to try anything or do anything. He treated everyone with respect and love," Alba said.
"He was never treating anybody differently because of who they were. He was really a guy's guy. And loved his daughter so much and talked about her all the time. He never cared about Hollywood. He never cared about the hype," she added.