Odesza (/oʊˈdɛzə/; stylized in all caps) is an American electronic music duo originating from Bellingham, Washington. It consists of Harrison Mills and Clayton Knight, known individually as Catacombkid and BeachesBeaches. They formed in 2012, shortly before Mills and Knight graduated from Western Washington University.

Their debut album, Summer's Gone, was released later in 2012 to acclaim in the underground electronic music community. After their debut extended play (EP), My Friends Never Die, in 2013, they released their second album, In Return, on September 9, 2014. It was the duo's debut release on Ninja Tune and its imprint, Counter Records. In 2016, "Say My Name" (RAC mix) gained the duo their first Grammy nomination (Best Remixed Recording, Non-Classical) at the 58th Annual Grammy Awards. A Moment Apart, their third studio album, was released on September 8, 2017. It reached number three on the Billboard 200, while topping the Top Electronic/Dance Albums Chart. It was nominated for Best Dance/Electronic Album, with "Line of Sight" also nominated for Best Dance Recording, at the 60th Annual Grammy Awards in 2018. ODESZA released their fourth studio album, The Last Goodbye, on July 22, 2022 through Ninja Tune. The album was nominated for Best Dance/Electronic Album for the 65th Grammy Awards.

The duo was also nominated in 2017 for Producer of the Year at the Electronic Music Awards. They have founded and operated their own record label, Foreign Family Collective, which distributes songs as well as visual art from artists. Furthermore, Billboard named Odesza as number 10 on their 2018 ranking of dance musicians, the Billboard Dance 100.

Harrison Mills and Clayton Knight met during their freshman year at Western Washington University. The two did not share the same educational interests. Knight studied physics and mathematics while Mills studied graphic design. They did not begin collaborating musically until their senior year in 2012 after befriending their early influence into music, DJ Maul-IE. As a child, Knight was classically trained in piano and later learned guitar.

The band's name is taken from the name of Mills' uncle's sunken vessel, which was named after the Ukrainian city of Odesa. Only his uncle and one other crew mate survived. Since the spelling "Odessa" was already being used by a Scottish synth band, they instead chose to use a form of the Hungarian spelling, replacing the "ss" with "sz". The correct spelling in Hungarian is “Odessza”.

Individually Mills is known as Catacombkid, and Knight is known as BeachesBeaches. In reference to how Mills got his nickname, he says, "I got into Aesop Rock and he has a song called 'Catacomb Kids.' I thought it sounded cool." On the other hand, regarding the story behind Knight's nickname, Knight says, "Honestly I was high in my bedroom making music one day…"

The duo quickly released their debut LP, Summer's Gone, on September 5, 2012. On November 9, 2012, Odesza performed their first show, opening for Teen Daze and Beat Connection in Bellingham, WA. Odesza was booked to open for Pretty Lights on his Analog Future Tour in the fall of 2013. Their first headline tour kicked off on March 12, 2014. On October 17, 2014, Odesza's In Return North American tour sold out 28 shows. Thirty-one Odesza tracks have reached the top on Hype Machine, including "How Did I Get Here", "Memories That You Call", "Lights", "All We Need" (Autograf Remix), among others. Their first festival performance at Sasquatch! Music Festival in George, Washington was followed by slots at over 20 festivals, including Coachella, SXSW, Hangout Festival, Lightning in a Bottle, Governor's Ball Music Festival, Bonnaroo Music Festival, Firefly Music Festival, Free Press Summer Fest, and Lollapalooza.

In March 2015, Odesza launched Foreign Family Collective, an outlet for musicians and visual artists alike. Their goal is to help upcoming artists gain more exposure by releasing one-off singles. As of December 2017, there have been 29 released singles.