“Especially proud to be a part of the Nike family today. #justdoit,” Williams, 36, tweeted along with an image of a different Nike ad that read: “It’s only a crazy dream until you do it.”
Her support comes after many called to boycott the company which unveiled Kaepernick, 30, as the new face of Nike’s 30th anniversary “Just Do It” campaign.
“Believe in something, even if it means sacrificing everything,” the Super Bowl quarterback’s ad reads.
Outraged by the announcement, many Nike fans took to social media to protest Nike and Kaepernick, who made headlines in August 2016 when he took a knee during the national anthem to protest racial injustice and police brutality.
“I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color,” Kaepernick said at the time.
“To me, this is bigger than football and it would be selfish on my part to look the other way,” the athlete added.
“@Nike Due to your support of C.K. in your coming adds, I as an American can no longer support your company. #boycottNike #IStandForOurFlag,” one user wrote with a video showing himself burning a number of Nike shoes.
Before Nike’s big reveal, Williams previously showed her support of Kaepernick last week at the U.S. Open.
“I think every athlete, every human, and definitely every African-American should be completely grateful and honored how Colin and Eric are doing so much more for the greater good,” Williams told the Associated Press about Kaepernick and fellow former San Francisco 49er Eric Reid, who also refused to stand for the anthem.
“They really use their platform in ways that is really unfathomable. I feel like they obviously have great respect from a lot of their peers, especially other athletes, people that really are looking for social change,” the mother of one added.
In addition to Williams, LeBron James shared Kaepernick’s ad on Instagram writing, “🗣🗣🗣🗣Just.Do.It ✊🏾 @kaepernick7.“
Rappers Big Sean, YG, producer Ava DuVernay also posted Kaepernick’s ad on their Instagram stories.