Johnny Marr (born John Martin Maher; 31 October 1963) is an English musician, singer, and songwriter. He was co-songwriter – with Morrissey – and guitarist of the Smiths between 1982–87, an English rock band formed in Manchester. Critics have called them the most important alternative rock band to emerge from the British independent music scene of the 1980s. Q magazine's Simon Goddard argued in 2007 that the Smiths were "the most influential British guitar group of the decade" and the "first indie outsiders to achieve mainstream success on their own terms". The NME named the Smiths the "most influential artist ever" in a 2002 poll, even topping the Beatles.

Marr has also been a member of Electronic, an alternative dance supergroup formed with New Order singer and guitarist Bernard Sumner; the The, an English musical and multimedia group led by singer/songwriter Matt Johnson; Modest Mouse, an American indie rock band formed in 1993 in Issaquah, Washington; and the Cribs, an English three-piece indie rock band originally from Wakefield, West Yorkshire. As well, he has worked as a prolific session musician. In 2013, he released a solo album titled The Messenger (2013).