The 21-year-old was held by Northumbria Police following an allegation made by a woman that she was attacked at a hotel in Jesmond, Newcastle between Wednesday and Thursday.
London-born Ranger, who lives in Forest Hall, North Tyneside, was still being questioned on Friday.
A police spokeswoman said: "On Thursday January 24 a woman reported to police that she had been raped overnight at a hotel in Jesmond.
"A 21-year-old man has been arrested at an address in Forest Hall on suspicion of rape."
Ranger angered fans by criticising them for booing after Newcastle lost to Reading at the weekend.
He went on to enrage them by apparently spelling his name out in £20 notes and posting a photo online.
A Newcastle United spokeswoman declined to comment.
Ranger, an England Under-19 international, has had a troubled time at Newcastle, and has been loaned to Sheffield Wednesday and Barnsley.
Back on the fringes of the first team at Newcastle, he tweeted on Saturday after the side's Premier League defeat: "Certain fans need to not come and support this team. Coming out to BOOO us Stay at home Don't need ur BOO's SAY NO MORE !!!"
He followed it up with: "Last thing from me. To all the fans. U are not forced to buy season tickets Or pay our wages Please remember that."
The response from the Magpies fans was fierce, with supporters demanding he never wear the black and white shirt again.
The day after, he tweeted: "God gives the hardest battles to the strongest soldiers !!"
Source: Newcastle United Mad