From today until Sunday 27 February, customers will get a coupon entitling them to 7p off a litre of fuel when they spend £40 in one of its stores.
It comes as petrol prices surged to a record high this week with predictions of further rises in coming weeks.
The AA said petrol surpassed 148p a litre on Sunday, rising above the previous record high of 147.72p on 21 November last year.
“We know that the cost of living increases are really beginning to bite for everyone in the UK and we want to help our customers by saving them money on one of their biggest expenses,” said Rachel Eyre, chief customer and marketing officer at Morrisons.
“With Covid restrictions now easing, customers are using their cars more often and we believe this offer will help them to spread their budgets further.”