Alexander David Turner (born 6 January 1986) is an English singer, songwriter, and record producer. He is well known as the frontman and principal songwriter of the rock band Arctic Monkeys, with whom he has released seven albums. He has also recorded with his side project involving Miles Kane, as the Last Shadow Puppets and also as a solo artist.

When Turner was 17, he and three friends formed Arctic Monkeys in their native Sheffield. Their debut album, Whatever People Say I Am, That's What I'm Not (2006), became the fastest-selling debut album in British history and was ranked at No. 30 on Rolling Stone's list of the greatest debut albums of all time, with the single "I Bet You Look Good on the Dancefloor" becoming a UK number-one hit. The band's subsequent studio albums, Favourite Worst Nightmare (2007), Humbug (2009), Suck It and See (2011), AM (2013), Tranquility Base Hotel & Casino (2018) and The Car (2022), have experimented with desert rock, indie pop, R&B, and lounge music. Arctic Monkeys headlined Glastonbury Festival in both 2007 and 2013, Reading and Leeds Festivals in 2014 and 2022, and performed during the 2012 London Summer Olympics opening ceremony.

As the co-frontmen of The Last Shadow Puppets, Turner and Miles Kane have released two orchestral pop albums: The Age of the Understatement (2008) and Everything You've Come to Expect (2016). Turner also provided an acoustic soundtrack for the feature film Submarine (2010), and co-wrote and co-produced Alexandra Savior's debut album Belladonna of Sadness (2017).

Turner's lyricism, ranging from kitchen sink realism to surrealist wordplay, has been widely praised throughout the music industry and the public. All but one of his nine studio albums have topped the UK Albums Chart. He has won seven Brit Awards, an Ivor Novello Award, and a Mercury Prize (he has been nominated six times).