21-year-old Guendouzi will spend the entire season in Berlin, but Hertha will not have an option to buy.
Guendouzi has fallen out of favour at Arsenal and hasn’t played since June when he clashed with Brighton striker Neal Maupay.
Hertha will compete in this season’s Europa League and can offer the Frenchman plenty of game time.
Bruno Labbadia’s men were beaten 4-3 by Bayern Munich on Sunday with Robert Lewandowski scoring all four goals for the German champions.
Rekik brothers on the way out
Centre-back Karim, 25, formerly of Manchester City, is already in Spain to finalise a move to Sevilla.
Karim Rekik ya en Sevilla pic.twitter.com/rlstQcBSJA
— Manolo Martín (@manolomartinc) October 4, 2020
The Dutch international joined Hertha from Marseille for €2.5m in 2017.
His younger brother Omar, 18, is hoping to seal a move to Arsenal where he would play for the under-23s.
Like Karim, Omar is a central defender by trade and has represented the Netherlands at youth level.