The pair, who have been dating for nine months, stepped out together at GQ's Men of the Year celebration at the Tate Modern in London, reported People magazine.
Schumer, 35, took to Instagram to share the picture of their first red carpet moment.
The "Trainwreck" star looked pretty in a black asymmetric one-shoulder mini dress while Hanisch, 29, was dapper in a color coordinated suit and tie.
The comedy star and her furniture designer boyfriend made their relationship public in January after meeting on a dating app, and have since been by each other's sides for numerous events including the Met Gala.
Other celebrities in attendance were Calvin Harris, Ashley Graham, Bella Hadid and her mother Yolanda, Michael Caine, Florence Welch and Chris Pine, who was named International Man of the Year.