The 23-year-old United States full-back, who spent last season on loan at Sunderland, is understood to have travelled to the north-east for a medical on Tuesday.
He would become the latest addition to a squad which has been overhauled by manager Rafael Benitez in the wake of relegation from the Premier League.
Yedlin's arrival would increase speculation over the future of Holland international Daryl Janmaat, who has been linked with a move away from St James' Park in recent weeks with West Ham and Watford reportedly among his suitors.
The Magpies have also been linked with Brentford midfielder Alan Judge, who is currently working his way back from a leg fracture.
Meanwhile, Newcastle defender Kevin Mbabu is to return to his native Switzerland to spend the season on loan at BSC Young Boys.
The 21-year-old full-back, who signed a two-year contract extension earlier this summer, made his Premier League debut in a 2-2 draw with Chelsea in September last year.
Mbabu, who joined the Magpies from Servette in January 2013, has five senior appearances to his name.