has released six top 10 platinum/multi platinum albums, five of which reached the top 4 of the ARIA Album Chart, including a No.1 and 2. He has also released ten top 15 singles, including five No. 1's. Sebastian is the only Australian male artist in Australian music history to achieve five No. 1 singles, and is equal third overall for all Australian acts. With 26 platinum and 2 gold accreditations and over 2 million sales in Australia, he has the highest sales of any Australian Idol contestant.Sebastian's debut single "Angels Brought Me Here" also reached No. 1 in four Asian countries and New Zealand. He had a second No. 1 single in New Zealand with "Who's That Girl", a No. 3 album and two other top 10 singles, and has four platinum and one gold accreditation there.
Sebastian has worked with a number of high profile American musicians. He co-wrote songs with Brian McKnight and Robin Thicke for his second album Beautiful Life, which also included a duet with Mya. The Memphis Album was recorded with members of the MGs including Steve Cropper, and they were his band on his 2008 Australian tour. Like It Like That features three tracks with John Mayer playing guitar and singing backing vocals, and "Art of Love", a duet with Jordin Sparks. This album was released in the US in 2010. "Who's That Girl" from his sixth album Twenty Ten features US rapper Eve.
During his career Sebastian has been nominated for ten ARIA Music Awards, including "Best Male Artist" and "Best Pop Release" in 2010. Previously, three of his albums received nominations for "Highest Selling Album", and "Angels Brought Me Here" won the 2004 ARIA for "Highest Selling Single". It was the first Australian artist single in music history to reach 4 x platinum, and in 2010 ARIA announced it was the highest selling song of the previous decade. "Like it Like That", the title track of his fifth album achieved triple platinum and was the highest selling Australian artist song of 2009. In 2011 "Who's That Girl" became only the fourth Australian artist single to ever reach 4 x platinum, and it was awarded the APRA Award for "Urban Work of the Year". Sebastian's other achievements include the " Channel V's Artist Of The Year Award" in 2004, Urban Music Awards for "Best Male Artist" in 2006 and "Best R&B Album" in 2007. In 2010 he was chosen as a judge on the Australian series of The X-Factor.