Man on the Moon II: The Legend of Mr. Rager is the second studio album by American rapper Kid Cudi. It was released on November 9, 2010, through Dream On and GOOD Music, and distributed by Universal Motown Records. It serves as a sequel to his debut studio album Man on the Moon: The End of Day (2009), and is the second installment of the Man on the Moon trilogy. Production for the album took place during 2009 to 2010 at various recording studios and was handled by long-time collaborators Emile Haynie and Plain Pat. It also featured contributions from Anthony Kilhoffer, Blended Babies, Chuck Inglish, Dot da Genius, Jim Jonsin, and Rami Beatz, among others. The album was supported by two singles: "Erase Me" and "Mr. Rager".

The album incorporates alternative and psychedelic elements to the sound that Cudi explored in his previous album. It features a blend of dark and emotional lyrics, exploring themes of depression, loneliness, detachment, and isolation. The album also highlights other topics, such as Cudi's former cocaine addiction, fame, and alcoholism, as well as family issues and women. The album features guest appearances from CeeLo Green, Mary J. Blige, Kanye West, Cage, St. Vincent, GLC, Chip tha Ripper, and Nicole Wray. Further contributors include Mike Dean, Larry Gold, Ken Lewis, Frank Romano, and Ray Bradley.

Man on the Moon II: The Legend of Mr. Rager debuted at number three on the US Billboard 200, selling 169,000 copies during its first week of release. The album received generally positive reviews from critics, due to its diverse change to the sound and continuing theme of the album. On March 27, 2018, the album was certified platinum by the Recording Industry Association of America (RIAA) for sales of more than a million copies in the United States.