Iris R. Hassenzahl is a German voice actress known for her work in dubbing anime and other productions for the German market. Born Iris Reinhardt Hassenzahl in 1986 in Hanau am Main, Germany, she is also credited professionally as Iris R. Hassenzahl or Iris Reinhardt Hassenzahl.

Hassenzahl's career is prominently defined by her extensive voice work in numerous anime series and films. She is particularly recognized for her long-standing association with the Fate franchise, where she has provided the German voice for the character Saber, also known as Artoria Pendragon, and her variant, Saber Alter. Her credits in this franchise include the television series Fate/Zero and Fate/stay night: Unlimited Blade Works, as well as the films Fate/stay night: Heaven's Feel - II. Lost Butterfly and Fate/stay night: Heaven's Feel - III. Spring Song. She also voiced the character Fô, a version of Artoria Pendragon, in the anime special Fate/Grand Order: First Order.

Another significant and recurring role for Hassenzahl is the character Erwin, whose real name is Riko Matsumoto, from the Girls und Panzer series. She has voiced this character across multiple installments, including the original Girls und Panzer television series, the OVA Girls und Panzer: This is the Real Anzio Battle!, the film Girls und Panzer der Film, and subsequent installments of the Girls und Panzer das Finale film series. This role represents a sustained collaboration with the franchise.

Beyond these signature roles, her anime voice acting portfolio is diverse. She voiced Lilith Asami in the television series Trinity Seven and had a role in Kill la Kill as Omiko Hakodate. Her other anime credits include characters in Corpse Party: Tortured Souls, Shirobako, and the Space Battleship Yamato reboots Star Blazers 2199 and Star Blazers 2202. She also contributed to the dubs of series like Samurai Girls and Glitter Force Doki Doki.

In addition to her work in animation, Hassenzahl's career includes voice work for live-action productions and television. Her filmography features the German dubs of films such as Dogtooth and the television series Wilde Zeiten - Alte Freunde neu gemischt!. She also appeared on screen in a 2012 episode of the long-running German children's television series Löwenzahn, playing the role of a pastry chef.