The Queen will reach the milestone on 9 September and the Mayor of Wolverhampton, Councillor Ian Brookfield, is to host a party for city youngsters aged 11 and under who share their birthday with the milestone date.
He is putting on a traditional party with a distinctly British feel including bunting, jelly and ice cream and a Punch and Judy show.
Only 50 places are available at the prestigious party and they will be awarded on a strictly first come first served basis.
The event will take place at Bantock House on 12 September.
On 9 September, Queen Elizabeth II will overtake her great great grandmother Queen Victoria to become Britain's longest reigning monarch. Victoria reigned for 63 years and seven months.
Councillor Brookfield said: "Her Majesty will become the longest reigning monarch in our history next month and I want to host this party for local children to join me in celebrating this truly special milestone.
"50 lucky youngsters will be able to come along and have a great afternoon with all sorts of traditional entertainment which I'm sure the Queen would approve of.
"The event will be like an old fashioned street party, but we're having it indoors so that there's no risk the weather will spoil things."
Parents or guardians of children aged 11 or under who have their birthday on 9 September are able to apply for a ticket to the party by calling the Mayor's office on 01902 554090 during office hours or emailing firstname.lastname@example.org
- released: Thursday 13 August, 2015