"Believe in something. Even if it means sacrificing everything", read a teaser for an ad Kaepernick tweeted.
Shares of Nike fell after tens of thousands of people used the hashtag #NikeBoycott on Twitter.
"I think it's a bad message and a message that shouldn't be sent", Trump said of Nike's new campaign.
San Francisco 49ers quarterback Colin Kaepernick (7) attempts a pass during the second half of play in the home opener at AT&T Stadium in Arlington, on Sunday, September 7, 2014.
Kaepernick made headlines worldwide in 2016 when he chose to kneel for the US national anthem as a protest against police brutality and racial inequality.
The score of supports who are vocally standing behind Nike and Kaepernick's politically charged team-up also includes Kobe Bryant, Russell Crowe, House of Cards star Michael Kelly, Common, and many others.
Following the release of the campaign, people on Twitter started the hashtags #BoycottNike and #JustBurnIt, because that'll send a message obviously.
Serena Williams praised Nike for creating a "powerful statement" by making Colin Kaepernick the face of an advertising campaign.
That campaign led to boycotts and the Kaepernick ad has been similarly divisive.
Trump has been a vocal opponent of athletes who kneel during the national anthem to raise awareness about police brutality against black Americans and other racial injustices.
Nike, on Monday, announced it was making the free-agent National Football League quarterback the face of its brand for its 30th anniversary, something that was both lauded and criticized by many.
While Nike officials were likely thrilled with the attention their campaign received, they probably didn't expect a plug from a man who doesn't believe women should be able to wear any of Nike's clothing.
The singer, whose signature hit with the multi-platinum selling Big & Rich is "Save a Horse (Ride a Cowboy)", followed it up saying to watch Nike stock by this time next week and responded to several tweets responding to the cut up socks. Others who support Kaepernick will gladly shift their dollars to Nike for its support of the former San Francisco 49ers quarterback, who is viewed as a hero to many for standing up for social issues even if it meant the National Football League ultimately would freeze him out.