Third Party (stylised Third ≡ Party) is a British progressive house DJ duo consisting of Jonnie Macaire and Harry Bass, based in Essex, London. They are best known for their single «Everyday Of My Life» and the collaboration «Lions in the Wild» with Dutch DJ Martin Garrix. They began their musical career as producers by releasing singles and remixes.

The duo met at school and via their mutual interest in music production, they formed Third Party. They pursued further musical education at a music technical college for a year, funding themselves with part-time jobs. They later performed as DJs at local clubs in London while continuing studio production.

In 2012, Third Party released three singles – «Lights» with Steve Angello, «Feel» with Cicada and «Thank You». In 2014, they released «Everyday of My Life» as a single. They founded Release Records, their own record label in 2015, in partnership with Armada Music. Third Party’s single «Alive» served as the label’s first release. On 27 May 2016, they released «Lions in the Wild» with Martin Garrix. Their debut studio album «Hope», featuring eleven songs was released on 24 February 2017. They began working on the album from late 2015. They are resident DJs at Ministry of Sound club.