The supermarket made the announcement to its 111,000 workers today.
The news comes just weeks before the conclusion of a takeover battle that will see the supermarket become a privately owned business. There have been concerns that staff welfare could drop under new ownership, but both suitors have vowed to maintain standards for employees.
It will be the first time the Big 4 grocer has kept stores closed on December 26 in living memory.
It follows the path of several rivals, who last year agreed to give staff the day off to spend time with families and loved ones after one of the hardest years in retail.
Joanne McGuiness, national officer at shop workers’ union Usdaw, said: “The last year-and-a-half has been unlike any other.
“The pandemic meant shop workers stepped up and kept essential services running. We welcome Morrisons doing the right thing by their staff with the closure of supermarkets on Boxing Day.
“Key workers have done so much this year and we are asking retailers to give their staff the longest possible break over the festive season to provide them with a well-deserved breather. We don’t think this is too much to ask for.”