Getting his name from his fast, rapid-fire lyrics, he released his first mixtape in 2006. In 2009, he became the first rapper to win at the Apollo Theater in Harlem, boosting his rise to popularity.
In 2011, while at SXSW, he caught the attention of Sean Combs, who signed him on to his record label, Bad Boy Records. His first EP, Half Naked & Almost Famous, dropped in 2012, with his debut album, Lace Up, arriving later that same year, which met with success. Since then, he has been nominated for a number of award categories, while his music continues to chart.
Beginning in 2019, he started to move away from hip-hop towards Pop Punk, forming a strong collaborative relationship with Travis Barker that resulted in far greater commercial success than he'd previously seen, and sparking a revival in mainstream interest in the genre in The New '20s.
Due to a certain beef he was involved in, Machine Gun Kelly makes appearances in Eminem's Slim Shady mythology. His unflattering characterisation under his rival's pen can be read about on Eminem Beefs.
- Stamp of Approval (2007
- Homecoming (2009)
- 100 Words and Running (2010)
- Lace Up: The Mixtape (2010)
- Rage Pack (2011)
- EST 4 Life (with Dub-O) (2012)
- Black Flag (2013)
- Fuck It (2015)
- Half Naked & Almost Famous (2012)
- Binge (2018)
- Lace Up (2012)
- General Admission (2015)
- Bloom (2017)
- Hotel Diablo (2019)
- Tickets To My Downfall (2020)
- Mainstream Sellout (2022)
- Beyond the Lights (2014) as Kid Culprit
- Nerve (2016) as Ty
- Viral (2016) as CJ
- Bird Box (2018) as Felix
- Big Time Adolescence (2019) as Nick
- Captive State (2019) as Jurgis
- The Dirt (2019) as Tommy Lee
- The King of Staten Island (2020) as Tattoo Shop Owner
- Project Power (2020) as Newt
- Downfalls High (2021) (director)
- Midnight in the Switchgrass (2021) as Calvin
- Jackass Forever (2022) as himself (guest appearance)
- Good Mourning (2022) as London (also director)
- The Cameo: Pete Davidson appears on interlude tracks from both Tickets To My Downfall and Mainstream Sellout, and plays a convenience store cashier in the music video for "Candy".
- Circling Birdies: Stars and hearts spin around his head when he's struck by a knock-out dart in the "Emo Girl" music video.
- Cover Version: In wake of George Floyd's death, he recorded a cover of Rage Against the Machine's "Killing in the Name" with blink-182's Travis Barker.
- Emo Teen: "Emo Girl" has him and singer Willow describing their love of these type of women, although not obviously teenagers.
- Motive Misidentification: Accused Eminem of dissing him and blackballing him from his radio station because of an old tweet he made in which he gushed about how Eminem's daughter was hot (she was underage at the time). In Eminem's Diss Track "Killshot", he reveals the real reason he dissed him is because "I just don't like you, prick".
- New Sound Album: His fifth album Tickets to My Downfall is a straightforward Pop Punk album in comparison to his past four albums, which are rooted in Hip-Hop with the latter Hotel Diablo incorporating Rap Rock.
- Persona Non Grata: He has repeatedly said that his feud with Eminem got him banned from the SiriusXM hip hop channel "Shade 45". Eminem has repeatedly denied this.
- Power Ballad: "Bad Things", a song about abusive love, is noticeably slower than most of his work, possibly in an attempt to appeal to more Top-40-friendly audience; it even features pop star Camila Cabello singing the hook.
- Pretty Fly for a White Guy: Early in his career he wore hip-hop clothing and tried to act "gangsta" in his songs (a good example of this being "Warning Shot"). Later he started dressing in an androgynous punk style similar to the only recently departed Lil Peep.
- Produce Pelting: Depicted happening to him on the cover of Mainstream Sellout.
- Rap Rock: Hotel Diablo adds some more rock elements to his usual Hip-Hop sound. Taken even further with Tickets to My Downfall which has been described as a pop-punk album.
- Record Producer: Since Tickets To My Downfall, his has mostly been Travis Barker.
- Sampling: "Bad Things" interpolates the hook from Fastball's "Out Of My Head", while "All I Know" does the same to "Knowledge" by Operation Ivy.
- Sequel Song: "WW4" on Mainstream Sellout is the sequel to "WWIII" on Tickets To My Downfall.
- The Stoner: As he told Megan Fox, "I am weed."
- Take That!: "Rap Devil" is this to Eminem's diss track "Not Alike", which was a jab towards him and Eminem in turn would return in response with "Killshot".
- Verbal Tic: Early on in his career, his were "Lace up" and "Kells".