The track is the second single from Mika’s highly new album, 'My Name Is Michael Holbrook', out on 4 October.
The new record is available from 18 January via Republic Records.
The new track arrives hot on the heels of ‘Sunflower’: the star's collaboration with Rae Sreummurd’s Swae Lee from the soundtrack to 'Spider-Man: Into The Spider-Verse.'
The trek kicks off on 21 February in Munich, Germany and visits 22 cities throughout the initial European leg.
'This Christmas Day' is the title track from the London-born star's first festive album, released through LAVA/Republic Records.
'Imagine' is the second song the star has released believed to be from her next album, provisionally-entitled 'Thank U, Next'.
The band say: "We are all so very honored and humbled to have been nominated for a Grammy Award, and so appreciative for the love and support we get from our fans."
The track is taken from the singer's fun-packed festive album 'This Christmas Day.'
The winners will be revealed on 10 February in a two-part ceremony at the Staples Center in Los Angeles.
The new film stars ‘Basketball Wives’ Evelyn Lozada, Lauren London, Tyga and more.
The 21-date trek takes in shows in Austin, Nashville, Boston, New York, Toronto, Los Angeles and more.
The star's recordings were previously signed to indie Big Machine Records and distributed via Universal on a worldwide basis
'Other People’s Stuff' is released through Republic Records on 7 December.
The trek is in support of the band's 'Anthem Of The Peaceful Army', released through Lava/Republic Records on 19 October.
The jaunt launches at Dublin's 3 Arena on 14 February and concludes at London's 02 Arena on 13 March.
These shows on ‘The John Mellencamp Show’ will start promptly at 8pm and will not have an opening act.