"I stand with those who are calling out the ingrained racism and violence toward people of color in our country," he wrote. "We have had enough."
There has been unrest across the United States after a Minneapolis police officer killed Floyd, a black man, last week. At least 30 cities have held protests calling for changes.
Jordan is encouraging the "peaceful expressions against injustice" from those marching in the streets.
The Basketball Hall of Famer and current owner of the Charlotte Hornets has defended the right to protest in the past, a topic that became divisive several years ago when it came to athletes.
"One of the fundamental rights this country is founded on was freedom of speech, and we have a long tradition of nonviolent, peaceful protest," Jordan said in 2017, per Rick Bonnell of the Charlotte Observer. "Those who exercise the right to peacefully express themselves should not be demonized or ostracized.
"At a time of increasing divisiveness and hate in this country, we should be looking for ways to work together and support each other and not create more division."
Jordan is the latest prominent member of the NBA community to speak on the protests. LeBron James has used social media to spread his message, while Kareem Abdul-Jabbar created an op-ed for the Los Angeles Times.