Hayes was born in Brisbane, Australia. He is the youngest of three children. At Mabel Park High School, Hayes appeared in the school musicals Man of Steel (playing Jimmy Olsen) in 1988 and Bye Bye Birdie (playing Albert) in 1989. He also sang at school concerts before graduating in 1989.

In 1993, Hayes answered an advertisement in a magazine placed by Daniel Jones for a lead singer for a band called Red Edge. Hayes was successful despite his voice breaking in the audition. The covers band broke up in 1994 and Hayes formed a partnership with Jones, which was initially going to be called Crush. However, there was another band in the UK which had the rights to the name so the pair called themselves Savage Garden, after a phrase used by Anne Rice to describe the world through the eyes of the main character in her novel The Vampire Lestat.

Savage Garden started recording their debut album in 1995 with producer Charles Fisher. Their first single "I Want You" released in 1996 was the best selling single by an Australian artist that year. The second single "To the Moon and Back" topped the Australian charts at the end of 1996. The third single "Truly Madly Deeply" was their second number one and was the best-selling Australian single of 1997. Their debut album, Savage Garden, was the best selling album in Australia during 1997 and the duo won ten ARIA awards.

Hayes moved to New York City to promote Savage Garden internationally while Daniel Jones stayed in Brisbane. The move proved to be successful with "Truly Madly Deeply" going to the top of the American charts in 1998. The Savage Garden album sold seven million copies in the US on the back of this success.

In New York City, Hayes wrote Affirmation. He had divorced his wife of several years. Parts of the album reflected the pain from the end of the relationship. Affirmation was released in 1999 and proved to be another hit with lead single "I Knew I Loved You" going to number one in the United States and the album selling six million copies by the end of 2000. The pair played the title track of the album at the closing ceremony of the 2000 Sydney Olympics.

Hayes moved to Sausalito, California in 2000. He became the public face of the duo doing most of the media. Hayes announced that Savage Garden had broken up in October 2001 during an off the record chat with an Australian journalist. When confronted with this information during the early morning hours, before an unrelated interview, Jones denied the break-up of the band. Still, the fact that Jones took a back seat in all promotional activities for Affirmation seems indicative that Jones was not content to remain within Savage Garden as it had operated in the past. The truth of the situation remained in the hands of the two members until an interview in a music publication in 2005 when John Woodruff confirmed that Daniel Jones had announced his intention of leaving Savage Garden prior to the promotion for Affirmation and Darren Hayes has guaranteed that Savage Garden will "never by any chance" reunite.

Hayes recorded his first solo album, Spin, which was released in 2002. Spin carried on in the same musical vein as Savage Garden, with a less soft rock sound and more edgy R&B vibe, although the first single "Insatiable" was a ballad, reaching Number 3 in Australia. Other singles "Strange Relationship", "Crush (1980 Me)" and "I Miss You" also performed well in charts.

Hayes spent two years working on his second solo album, The Tension and the Spark. The album marked a bold change of direction from Hayes. Production was almost entirely electronic, with acoustic instruments buried under walls of sequenced sounds. Although artistically this was a huge step forward and earned Hayes the strongest praise of his career, it seemed to alienate a large portion of his audience who were expecting another album of radio friendly pop songs.

Hayes finished recording his third solo album This Delicate Thing We've Made in 2007. The album was released on August 20, 2007 on Hayes' own record label Powdered Sugar, while the first single "On the Verge of Something Wonderful" was released in Australia on July 28, 2007 and in the UK and online on August 6, 2007.