Made In Chelsea star Ollie donned a cap, baggy trousers and gold-frame glasses to impersonate the N-Dubz singer - and his image overhaul impressed his fellow housemates!
Ollie even mastered Dappy's walk and wore his trousers down low to complete the look! Dappy seemed overwhelmed with the transformation, saying: "Oh my God, you're rocking it."
The pair then gathered with the rest of the housemates on the sofas, and began a bit of role-play, where Dappy tried to speak in Ollie's accent.
We're sure the moment came as light relief to the housemates, who have had their fair share of tension in the house.
Other than the ongoing drama surrounding Lee Ryan and Jasmine Waltz's blossoming romance, yesterday, Lionel Blair and Luisa Sizzman were embroiled in an explosive row.
Celebrity Big Brother continues tonight at 9pm on Channel 5.
Watch Ollie in the video below: