Alexander Giannascoli (born February 3, 1993), better known by his stage names Alex G or, formerly, (Sandy) Alex G, is an American musician, producer, and singer-songwriter. During live performances, Alex G is joined by his longtime backing band, which features Sam Acchione (guitar), John Heywood (bass) and Tom Kelly (drums).

Giannascoli started his career playing in local bands before he decided to pursue a solo music career. At 17, he began to release his own music and released his first album under the name Alex G in 2010. His first solo work was DIY self-releases on Bandcamp before his label debut, DSU (2014), released on Orchid Tapes to critical acclaim from various publications. He later signed with Lucky Number, who reissued his earlier releases, Rules and Trick (2012).

In 2015, he signed with Domino Recording Company and released his sixth studio album, Beach Music. He followed it in 2017 with Rocket, which received further acclaim and recognition. Giannascoli's eighth studio album, House of Sugar, was released in 2019. In 2022, Alex scored American director Jane Schoenbrun's film We're All Going to the World's Fair, and later released his ninth album, God Save the Animals. He signed with RCA Records in early 2024, and additionally scored Schoenbrun's I Saw the TV Glow. His tenth album, Headlights, was released on July 18, 2025.