The organisation said the uniform combines the charity’s heritage with modern colours and prints.
The range is made up of 30 items of clothing, 15 accessories and neckerchiefs – with prices starting at £12, for a T-shirt.
Design features include hidden pockets in waist bands, thumb holes, and badge sashes which double as cross-body bags.
This is the first time in 30 years Girlguiding has updated its entire range at the same time.
Oswald said the range was “all about providing girls with the freedom to express themselves, whilst feeling part of our amazing organisation”.
Members do not have to buy the new range straightaway, the website explains, and they can continue to wear the old uniform until they need a replacement.
A Girlguiding survey in June of 2,000 girls aged six to 16 in the UK found that 93% said they felt most comfortable when able to choose how they styled themselves.
Angellica Bell, a Girlguiding ambassador and presenter, said the new design gives “girls and volunteers the freedom to style it the way that suits them”.
She added: “The new uniform empowers girls and volunteers to embrace their individuality.”