The Black Quill, also known as the Blood Quill, was a quill created by Dolores Umbridge. The feather of the quill was long and black, and the nib was extremely sharp. It was used to torture the user of the quill by making them write in their own blood. The words they wrote would be etched onto the paper, carving the words into the back of their hand, before healing over. Using this quill repeatedly left a scar.

Umbridge used the quill on students who disobeyed her, with her notable target being Harry Potter, who was being discredited on his claims that Voldemort had returned. It was also used on Lee Jordan, who made fun of Educational Decree 26, which forbade teachers from issuing information outside of the subject they taught. There were likely other students who were subjected to the Black Quill, but it was not reported.