The "Born This Way" singer initially scored a chart hit with her third studio release in 2013, but it received mixed reviews and suffered a large drop in sales after its first week of release, prompting some to deem the project a failure.
At the time, GaGa hit back at the criticism, insisting detractors simply failed to understand the concept of "Artpop", but six years on, it appears even she has forgotten all about that period of her career.
The pop superstar caught fans off guard on Monday, November 11 when she took to Twitter and simply wrote, "I don't remember ARTPOP."
She didn't expand on her statement, but her admission has led to a backlash from followers, with many expressing their disbelief at her blunt comment.
"I can't believe she'd betray us like this," wrote one fan, while another posted, "How can you not remember your best album??"
Others trolled GaGa by replying to the message with screenshots of a tweet she had shared back in 2013, when she declared ARTPOP "the album of the millennium."
She has yet to respond to the online uproar.