The 22-year-old full-back has joined the Millers on a short-term deal to provide cover for the injured Mark Bradley.
Tavernier has made nine senior appearances for the Magpies although he has yet to start a Premier League game with only two substitute appearances in the top flight.
He has previously had loan spells with Gateshead, Carlisle, Sheffield Wednesday, MK Dons and Shrewsbury.
"James is a very accomplished full-back, who can play on either side of the pitch and if needed can step in and do an excellent job at centre-back if required," said Rotherham boss Steve Evans.
"With the injury to Mark Bradley, and Rob Milsom who covers us at left-back also having a minor injury issue, this is an excellent signing for us."
Tavernier is likely to make his Rotherham debut in Saturday's home match against Gillingham.