Marquise Brown pleaded guilty to an excessive speeding charge on Wednesday ... six months after cops accused the NFL star of going 126 MPH in a 65 MPH zone.
The Cardinals receiver showed up to an Arizona courtroom to enter the plea ... and you can see in video of the hearing, obtained by TMZ Sports, he was wearing a black sweatshirt and black pants for the proceedings.
He didn't speak much while in court, though he and his attorney did tell the judge he was changing his initial plea of not guilty and pleading guilty to a misdemeanor charge of excessive speed.