The retailers are reducing the price of a pint to 90p, in order to match other grocers.
While the drop will be welcomed by people struggling with higher living costs, milk still costs more than double the average price before Covid.
In March 2020, a pint of milk was around 43p, according to official data.
All five supermarkets have confirmed the reductions in price will not affect how much they pay farmers.
Tesco said it made the decision because its costs for buying in milk had fallen.
Asda said that it had taken “swift action to reduce the price of milk as commodity prices have eased”.
Arla, the UK’s largest dairy producer, said in March that the price of milk was already expected to fall by around 5.3p per litre this month because of rising supplies and falling demand from cost-conscious shoppers.
The move comes at a time when food inflation is at its highest level since 1978. The latest official data shows that food prices increased by 18.2% in the year to February.
Milk alone has risen by 43% in price over the same period, one of many staples, including cheese and eggs, which have surged in cost and squeezed household budgets.
How milk prices will change:
One pint: from 95p to 90p
Two pints: from £1.30 to £1.25
Four pints: from £1.65 to £1.55
Some analysts have suggested that supermarkets reducing their prices is a possible sign that hikes in the cost of a weekly shop could be starting to ease.
Arthur Fearnall, a farmer and board director at Arla Foods, said: “While some prices for dairy categories are seeing early signs of levelling out, the severity of the on-going cost of living crisis and volatile economic environment is continuing to negatively impact consumer demand for both conventional and organic milk.”
Paul Savage, agriculture director at Arla, said milk supplies in the UK rose by 3.2% in March compared to the same month last year. “When coupled with a decline in dairy consumption and an overall decline in shopping spending, with 75% of people cutting expenditure on food, this is creating a change in the supply and demand of milk,” he said.
Sainsbury’s said with “costs going up, we are working hard to keep prices low, especially on the everyday essentials people buy the most”.
Recent research revealed nine out of 10 shoppers reported feeling concerned about rising food prices, according to Barclays.
Around 62% said they were finding ways to reduce the cost of their weekly shop, a report showed.
On Thursday, Tesco announced its full-year results and admitted that customers had faced “an incredibly tough year” with prices soaring.
Tesco’s chief executive Ken Murphy said that he expected prices to keep rising throughout the first half of this year but they would then “moderate”.
Tesco said that while its full-year sales had risen by 7% to £66bn, pre-tax profits dropped 51% to £1bn. It said it had faced “unprecedented” rises in prices charged by its suppliers.
Separately, Sainsbury’s has announced a major restructuring of how its logistics operations work, affecting around 7,000 staff throughout the country.
The company said that no one would lose their job or get moved to worse contractual terms.
