Guy Theodore Sebastian (born 26 October 1981) is an Australian singer and songwriter who was the winner of the first Australian Idol in 2003, and a judge on Australia’s The X Factor in 2010, 2011, 2012, 2015 and 2016. He represented Australia at the 2015 Eurovision Song Contest, finishing in 5th place. Sebastian is a coach for The Voice Australia in 2019. 
Sebastian has released nine top ten albums, including two number ones. The first seven all gained either platinum or multi-platinum certification. He has also achieved twenty two top twenty singles, with thirteen reaching the top ten, including six number ones. He is the only Australian male artist in Australian chart history to achieve six number one singles, and places third overall for all Australian acts. Eight of his singles have been certified multi-platinum, including the 11× platinum "Battle Scars". His debut single "Angels Brought Me Here" was the highest selling song in Australia last decade. With 62 platinum and five gold certifications and combined album and single sales of over 4.5 million in Australia, he has the highest certifications and sales of any Australian Idol contestant.Sebastian has worked with a number of notable American musicians, including Brian McKnight, Robin Thicke, Steve Cropper, John Mayer, Jordin Sparks, Eve and Lupe Fiasco. "Battle Scars", a collaboration with Fiasco, spent 20 weeks on the US Billboard Hot 100 chart, peaking at number 71 and achieved platinum certification. "Battle Scars" also reached number two in Norway and New Zealand. Sebastian has reached the top ten in New Zealand with an album and six singles, including two number ones, and gained six platinum and three gold certifications there. In 2015 his Eurovision song charted in the top 50 in five European countries.During his career Sebastian has received 28 ARIA Award nominations, winning four including Best Pop Release and Best Live Act. Other awards include the APRA Urban Work of the Year, the [V] Oz Artist of the Year, Urban Music Awards for Best Male Artist and Best R&B Album, and an International Songwriting Competition award for "Battle Scars". Sebastian has sung at many notable events, including performing for Pope Benedict XVI, Oprah Winfrey and Queen Elizabeth II. He has a strong commitment to charity, and was previously an ambassador for World Vision Australia and the Australian Red Cross. He has created his own foundation, The Sebastian Foundation, with his wife Jules. Sebastian was made a Member of the Order of Australia (AM) in the 2019 Queen’s Birthday Honours in recognition of his significant service to music and charity.