'Boomerang' singer Nicole was a proud girlfriend as she cuddled up to Lewis' bulldog Roscoe in a photo posted to Instagram (21 September).
Lewis took the lead in the World Championship for the first time in four months, so Sunday's win was a pretty special moment.
Captioning the photo, Nicole said: "Me & Roscoe so proud of you babe @lewishamilton winning #f1 #SingaporeGP #1 XO." Aww!
After congratulating Lewis, former X Factor judge Nicole had her own work to attend to, as she told fans she was getting ready for a secret concert in London - and Roscoe was right by her side.
Posing for another photo with her backing dancers, Nicole said: "Rehearsing for my private gig in #London tonight w/our mascot #TeamRoscoe."
And it seems the top secret gig was a success, as Nicole took to the streets of London with her girls, and Roscoe, and wore her comfy hotel slippers!
She said: "Late night walking Roscoe on the streets of London after a great show tonight with my girls #hotelslippers."
Last week, Nicole announced her second studio album will be called Big Fat Lie, which is due for release on 20 October.
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Watch Nicole's video for 'On The Rocks' below: