The 'Only Love Can Hurt Like This' hitmaker and the jazz singer will release their original track, 'Christmas Prayer', on Friday (27.11.20).
As per a press release, it’s a "timeless, uplifting love song. With jingle bells and both Paloma’s unmistakable voice and Porter’s smooth."
Paloma said: “I love Xmas and this year I think we need it more than ever. This song lifts the spirit and gives us the optimism we need!”
Gregory added: "Working on this Christmas song together with Paloma has been fun, I hope the passion and sheer joy that we put into this record will bring a little magic to everyone this Christmas! In the spirit of giving, Paloma will join me on 'The Hang' (My podcast) on New Years Eve - so tune in to ring in a bright future for us all in 2021."
The pair recently featured on the Children in Need charity cover of Oasis' hit 'Stop Crying Your Heart Out', which also featured the likes of Cher, Kylie Minogue, Nile Rodgers, Lenny Kravitz and Robbie Williams.
Paloma released her fifth studio album, 'Infinite Things', earlier this month.
And the British star admitted it will leave the listener both shocked and liberated.
The collection deals with becoming a mother and her own relationship with long-term boyfriend Leyman Lahcine.
Paloma - who is currently pregnant with her second child - said: "My USP is the fact that I am brutally honest.
"Some people find it shocking and some people find it liberating. And I feel like this album will do both of those things.”
As for Gregory, the Grammy-winner’s last studio album was August’s ‘All Rise’.
There is nothing more uplifting in this world than watching Billie Eilish - the face of moody teen angst - having so much fun in the video for her...
There's a lot to look forward to in the first summer month of 2021, including lawn tennis, World Music Day and a whole raft of new and exciting...