Iason Chronis (Greek: Ιάσων Χρόνης; born 17 January 1980), better known as Mason, is a Dutch DJ and record producer.

Mason plays live shows as well as DJ sets and has performed at festivals such as Sensation White, Dance Valley, Tomorrowland, Nature One, Creamfields, Global Gathering and clubs such as Fabric, Ministry of Sound, Green Valley, Space Ibiza, Zouk, Octagon, Air and many others with over a thousand shows in more than 50 countries around the world.

Mason is the organiser behind several parties throughout the Netherlands, including the Animal Language Kafe Rave and Avondwinkel at Club Nyx in Amsterdam.

In 1999, he took a four-year course in Music Composition and Performance, which he graduated with honours and for which he received an award from the Dutch royal family.

During his world tour with Tiësto in 2004, he played the violin during a live performance of "Lethal Industry", as well as being Tiesto's warm up DJ.

In 2011, he released his debut album They Are Among Us, which featured collaborations with Róisín Murphy, DMC, Sam Sparro, Kurtis Blow and Aqualung.

In 2015, his single "Papapapa" on Loulou Records reached the number 1 position on the online DJ store Beatport.

In 2016, Mason signed to Island Records and began work on material with US hip hop artist Azealia Banks.

In 2022 he worked together with NY Hiphop artists Jungle Brothers Afrika Baby Bam and founded his own girl vocal trio 'The Masonettes', that accompany him on certain records and shows.

Later that year he released his 4th album 'Chroma Panorama', on which he collaborated with Sophie Barker (Zero 7), Dragonette, Jack Garratt, Sweetie Irie (Gorillaz), Poppy Hankin (Girl Ray) and many others.