The incident occurred early in the second half of the frenetic north-east clash when Newcastle's Sven Botman was being treated for a head injury, causing referee Anthony Taylor to briefly stop the game.
"Today's match between Newcastle United and Sunderland was temporarily paused during the second half after a report of discriminatory abuse from the crowd, directed at Sunderland’s Lutsharel Geertruida," the league statement said.
"This is in line with the Premier League's on-field anti-discrimination protocol. The incident at St James’ Park will now be fully investigated. We offer our full support to the player and both clubs."
Newcastle United also offered their support to the 25-year-old Dutch defender.
"Our stance is clear - we do not tolerate discrimination of any form. We will work with the authorities to fully investigate and will ensure any individuals are identified and held accountable," a Newcastle spokesperson said.
The incident took the shine of a superb second-half performance by Sunderland, who came back from a goal down and snatched the three points with a 90th-minute goal from striker Brian Brobbey.
"He (Geertruida) looks OK. It is unacceptable, and important to report and manage the situation properly. He looks OK, but we need to support him," Sunderland coach Regis le Bris said.