Kate Middleton recycled a royal blue Missoni dress with frayed edges that she last wore in public on a trip to Fortnum and Mason with the Queen and Camilla on 1 March while William was still in the Falklands.
The royal party appeared in good spirits, despite the fact that, as William said in his speech, Philip "sadly couldn't be with us today," as he is still recuperating from a bladder infection which landed him in hospital for five days in the midst of the Jubilee celebrations.
The Duchess of Cambridge paired her coat with a navy cocktail hat by Rachel Trevor Morgan, navy court shoes and a quilted black clutch bag.
Prince William and Kate, who had travelled to Nottingham by car, welcomed the monarch off the Royal Train at the town's railway station.
A handful of passengers were gathered on the opposite side of the tracks and William called over to them, "Are you waiting for the same train we are?"
Up to 5,000 people packed into the city centre square, waving Union flags, many of whom had waited in the cold since 5am.
It is the first official "away day" engagement the Duke and Duchess have attended with the Queen as a couple.
Day two of the Queen's East Midlands Diamond Jubilee tour will continue tomorrow with visits to Stevenage and Hatfield. later today, the Queen will travel to Burghley House in Stamford, Lincolnshire, where she will be joined by 10,000 guests at a Diamond Jubilee Picnic.
There was a brief moment of chaos after the crowd broke through barriers to get a better view of the royals.
Later in the day, Prince William started a kids' obstacle race with the Queen and Kate watching intently and laughing, and there were more laughs when Kate and William inspected a foam javelin used by the chioldren.