LeBron James and Serena Williams show their support for Nike following launch of Colin Kaepernick ad

Two of the biggest names in sports, who also happen to have contracts with Nike, have spoken out in support of the company following the launch of its ad campaign featuring former San Francisco 49ers quarterback and social activist Colin Kaepernick.

Lakers superstar LeBron James said, “I stand with Nike, all day, every day,” as he accepted the Icon 360 award from Harlem’s Fashion Row in New York on Tuesday night. And 23-time Grand Slam champion Serena Williams tweeted a day earlier, “Especially proud to be a part of the Nike family today.”

Kaepernick, who was the San Francisco 49ers’ starting quarterback in the Super Bowl following the 2011 season, started a movement when he refused to stand for the national anthem before games during the 2016 season. He opted out of his contract with the 49ers the following offseason and has not landed with another team.

On Monday, he became one of the faces of Nike’s 30th anniversary “Just Do It” campaign. In addition to ads, Kaepernick will also create an apparel line for the company.

Predictably, the decision prompted strong reactions from both Kaepernick’s critics and his supporters. James and Williams fell into the latter category.

James posted Kaepernick’s ad on Instagram on Monday.

At the awards show Tuesday, the four-time NBA MVP referenced Kaepernick by saying he stood “for anybody who believes in change.”

Williams spoke more about Kaepernick and Nike following her 6-4, 6-3 victory over Karolina Pliskova in the U.S. Open quarterfinals Tuesday night.

“He’s done a lot for the African American community, and it’s cost him a lot,” Williams said of Kaepernick. “It’s sad. But he continues to do the best that he can to support.

“Having a huge company back him, you know, could be controversial for this company, but they’re not afraid. I feel like that was a really powerful statement to a lot of other companies.”

charles.schilken@latimes.com

Twitter: @chewkiii