According to reports, Benitez is keen on a move for the Frenchman - who has netted six goals in nine appearances this season.
While the Spaniard remains unaware of what his January transfer budget will be, it is believed that he is growing ever-more optimistic that Mike Ashley will be prepare to break the club’s long-standing transfer record during the winter window.
Benitez is thought to be keen on three new additions in January, with attacking reinforcements top of his list.
As well as an out-and-striker, Newcastle are keen on a number ten to rival Ayoze Perez - while a move for a left-back could also be sought.
But Haller is believed to be the number one target, although Newcastle could face competition from Dortmund for his services.
The initial report suggests that the Magpies are confident that they can lure the striker to Tyneside as Benitez closes in on his top transfer target.
Haller has previously been linked with the club, but what do we know about the frontman?
The 6ft 3in striker began his career at Auxerre in Ligue 1, going on to make over 50 appearances for the club during a fruitful spell.
But in December 2014, having struggled to nail down a starting place at AJA, he was shipped out on loan to FC Utrecht in Holland.
He impressed in the Eredivisie, netting 11 teams in 17 appearances while on loan before the move was made permanent.
44 goals in 85 appearances followed as Haller carved out a reputation as one of Europe’s most promising strikers.
Now 24, the frontman is one season into a four-year deal in Frankfurt, where he has continued to make waves.
Benitez was thought to be keen before, and the Spaniard now seems hopeful of sealing a deal for the French U21 international once the transfer window opens.