Troye Sivan Mellet ( TROY sih-VAHN; born 5 June 1995) is an Australian singer-songwriter and actor. After gaining popularity as a singer on YouTube and in Australian talent competitions, Sivan signed with EMI Australia in 2013 and released his third EP, TRXYE (2014), which peaked at number five on the US Billboard 200. Its lead single, "Happy Little Pill", reached the top 10 on Australian music charts. In 2015, he released his fourth extended play, Wild, followed by his debut studio album, Blue Neighbourhood. The album's lead single, "Youth", became Sivan's first single to enter the top 40 of the Billboard Hot 100 chart, peaking at number 23.

His second studio album, Bloom (2018), reached the top five in Australia and the US. Its lead single, "My My My!", became Sivan's second number-one single on the Billboard Dance Club Songs chart. In 2020, his EP In a Dream was released. In 2023, he released his third album, Something to Give Each Other, on 13 October. The album's three singles, "Rush", "Got Me Started", and "One of Your Girls", all reached the top 40 of the UK Singles Chart and the ARIA Singles Chart, while both "Rush" and "One of Your Girls" charted on the Billboard Hot 100. For the track "Rush", Sivan received his first Grammy Award nominations, one for Best Pop Dance Recording and another for Best Music Video.

As an actor, Sivan portrayed the younger Wolverine in X-Men Origins: Wolverine (2009) and starred as the titular character in the Spud film trilogy (2010–2014). In 2017, he became the youngest recipient of the GLAAD Stephen F. Kolzak Award. In 2018, he received a Golden Globe nomination for Best Original Song for "Revelation", from the film Boy Erased, in which he also had a supporting acting role. He has since starred in the film Three Months (2022) and the HBO series The Idol (2023).