At Abbeyfield House the 12 residents were joined by committee members and staff to raise a glass to celebrate the monarch's birthday.
Abbeyfield housekeeper Sharon Smith said the residents had a great time organising the event then dressing up for the party.
Ms Smith said the residents were a loyal, royal bunch who wanted to mark the Queen's birthday, with the party still going at 6pm last night.
Queen Elizabeth II was born on April 21, 1926. She became Queen on February 6, 1952 and became the longest-reigning British monarch on September 9, 2015, when she surpassed the reign of her great great grandmother, Queen Victoria.
New Zealand Post is celebrating the Queen's 90th birthday with a special series of stamps and a limited edition silver coin.
To mark her birthday, New Zealand Post has produced "lenticular" or moving stamps that feature nine different images of the Queen on just three stamps.