"I Knew I Loved You" is a song by Australian pop duo Savage Garden, released through Roadshow Music and Columbia Records as the second single from their second and final studio album, Affirmation (1999). The song was created as an attempt to replicate the composition of Savage Garden's previous single "Truly Madly Deeply". The track was serviced to US adult contemporary and top 40 radio in September 1999 and was issued commercially in Australia on 28 September 1999.

Darren Stanley Hayes is an Australian singer, songwriter, music producer and composer. He was the frontman and singer of the pop duo Savage Garden until their disbandment. Their 1997 album Savage Garden peaked at number 1 in Australia, number 2 in the United Kingdom and number 3 in the United States. It spawned the singles "I Want You", "To the Moon and Back", and Australian and US number 1 "Truly Madly Deeply". The duo followed the success of their debut album with Affirmation (1999), which provided additional hits such as Australian and US number 1 "I Knew I Loved You", and Australian number 3 "The Animal Song". Savage Garden parted ways in 2001.