The cute couple were spotted at the BBC Children in Need dinner, (held the Grosvenor House Hotel in the capital), where they were joined by stars including JLS, Gary Barlow and Ellie Goulding.
40-year-old Dermot kept up his well dressed reputation, by donning a simple black suit and a skinny black tie, which was not too different from the tailored ensembles he has been seen wearing while hosting The X Factor this year.
His wife Dee - who he married in Kent last September - stuck with the same monochrome colour scheme by slipping into a glamorous black dress that featured a split at the front and a skinny black waist belt to flatter her figure.
She also sported a white jacket with a furry collar, which no doubt kept her warm in the chilly London weather.
Dee completed her look with a pair of peep toe heels and a black clutch bag, while sweeping her hair to one side and adding a few curls.
Dermot appeared to be the perfect gentleman on their night out yesterday (11 November), as he held tightly onto Dee's hand when they left the hotel and helped her into their taxi.
Over the weekend, the cheeky X Factor presenter joined the ITV show's judges Nicole Scherzinger, Louis Walsh, Gary Barlow and Sharon Osbourne for dinner in the capital.
He took Dee along with him too and she soon hit it off with Xtra Factor's Caroline Flack, who later tweeted that her evening with the O'Learys had been "ace".
What do you think of Dee's dress? Let us know below, as the best comment each week wins £50!