The German retailer says the range will go on sale on July 24 and is the country's cheapest.
Trousers and skirts cost £1.50 each, a sweater or polo shirt is just £1.25 and shirts and blouses will go for £1.25.
The range also extends to PE kits, padded coats, shoes, and even £6.95 football boots.
With the average cost of a full uniform said to range from £156 for primary schools to £285 for secondary schools in some areas, the supermarket offerings have been extraordinarily popular with parents.
But although hard-pressed mums and dads will welcome the relief on their wallets, there are concerns that cheap, mass-produced, poor quality school uniforms are a false economy as they will not last long once worn and washed regularly.
Mum Kelly Rose Bradford, who wrote about this subject recently, said: "I have to ask myself this: would I go out to work in an outfit of dubious quality which cost just £4? One which I regarded as so cheap that it didn't matter what happened to it, I could just re-purchase it?
"Or because it wasn't the style of clothes I would chose to wear outside of work, it wasn't a problem if it was ill fitting, poorly made and looked like a sack-cloth once on?
"No matter how hard the supermarket try and tempt me with their cut price uniforms, I remain resolute in my belief of buy cheap, buy twice."
However, Aldi said the new range had been rigorously tested to ensure its white items did not discolour, hems did not drop and knee areas did not rip.
There are also worries about the conditions of the workers who make the uniforms in Bangladesh.
But a spokesman for Aldi said: "We promote workplace practices and conditions that are safe, fair and legal for all those involved in making our products."
Despite these protestations, Aldi's £4 uniforms – and the price war they are bound to start - have been broadly welcomed.
Gillian Guy, chief executive of Citizens Advice, said: "Back to school costs are a dark cloud over the summer for mums and dads. Last year Citizens Advice found that one in four parents were borrowing money to pay for new school uniforms.
"Schools and academies need to be conscious of the financial squeeze on families and give parents options to keep uniform costs down."
Aldi said the equivalent items in its £4 uniform would cost £6.75 at Tesco, £7.33 at Sainsbury's and £7.50 at Asda.
However, Sainsbury's disputes this, saying that it charges £6.17 for the same three items.
Unlike other retailers, Aldi has a flat price range across all sizes from ages four to 11.
Tony Baines, managing director for corporate buying at Aldi, said: "The run up to the new term can be a stressful time for families. As a result, we were keen to offer parents the opportunity to stock up on superior school uniforms and accessories ahead of the new term without breaking the bank.
"We are therefore delighted to provide our customers with a fantastic quality school uniform range at the lowest price available in any supermarket."
What do you think?
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