The decline continues a recent downward trend with inflation at 1.8% in January.
The Consumer Prices Index including owner occupiers’ housing costs (CPIH) 12-month inflation rate was also 1.5% in March, falling from 1.7% in February.
ONS said the largest contribution to the CPIH 12-month inflation rate change in March was from housing, water, electricity, gas and other fuels.
Falls in the price of motor fuels and clothing resulted in the largest downward pressure in the CPIH 12-month inflation rate between February and March 2020.
Rises in air fares produced the largest upward pressure.
Robert Alster, head of investment services at Close Brothers Asset Management, said: “A collapse in consumer demand combined with plummeting oil prices meant that declining inflation in March was inevitable, and is likely to continue through the duration of the Covid-19 crisis."
Most of the data for the latest figures was collected before the lockdown occurred and ONS says collecting future inflation data may be more challenging as so many shops are closed.
ONS said: “There will inevitably be challenges around some of our collection activities, as approximately 45% of the CPIH basket is physically collected in stores across 140 locations in the UK.”
Recently the UK Statistics Authority extended its consultation on dropping or merging the RPI inflation measure, used for the indexation of many pensions, from 22 April to 21 August.