In late 2008, Sebastian Ingrosso, Steve Angello, and Axwell formed the Swedish House Mafia with Eric Prydz not joining, saying he is a control freak and cannot abide with collaborations even with close friends.

[1] Around this time Swedish House Mafia released two songs, "Get Dumb" and "Leave the World Behind", however these weren't credited under the group name.

In 2009 Ingrosso made his debut on the DJ Mag top 100 DJs, charting at number 25, the highest new entry that year.

The album also contained solo work by Sebastian Ingrosso such as the songs "Kidos" and "Meich", plus his remix of "Silvia" by Miike Snow.

[4] In July, Swedish House Mafia performed at Tomorrowland for the third consecutive year, this time heading the event and opening Night 2.

The same month Sebastian Ingrosso released his collaboration with Tommy Trash entitled "Reload", this along with "Calling (Lose My Mind)" would feature on Swedish House Mafia's second studio/compilation album Until Now.

At one of their last performances of the tour, at Madison Square Garden Ingrosso famously broke the sound barrier as he was drumming so quickly with his drumpad.

In July, Sebastian Ingrosso made his Tomorrowland debut as a solo artist, performing the main stage on Night 1.

[9] On 29 June, Axwell Λ Ingrosso released their first single since their debut studio album, More Than You Know, featuring British singer RØMANS called "Dancing Alone".

[13][14] In August 2018, Axwell Λ Ingrosso announced that they would be going on hiatus in order to focus on the Swedish House Mafia reunion and 2019 tour.

[17] In addition, he is a childhood friend of fellow Swedish House Mafia member Steve Angello,[18] meeting at age six.