Mainstream Sellout (stylized in all lowercase) is the sixth studio album by American musician Machine Gun Kelly, released on March 25, 2022, through Bad Boy Records and Interscope Records. It is his second collaborative project with drummer and producer Travis Barker, following 2020's Tickets to My Downfall. The album was initially announced in August 2021 under the title Born with Horns, before being renamed in January 2022.