Reports on Thursday had suggested that Brawn's future as Team Principal was uncertain but Hamilton has claimed that the 58-year-old has made it clear that he is focused on succeeding at Mercedes.
The Brit told Sky Sports news: "Of course, when I was making the decision definitely he was on the pros and cons list.
"He's had a great career, he's got great success and he's a great part of the team. We need that figurehead in the team to help steer us the way.
"So we definitely all look to him. But he's reassured me that he's here to stay and he's here to work as hard as he can with me and the rest of the team to win."
Hamilton joined Mercedes after leaving McLaren at the end of last season.