Sri Lankan President Maithripala Sirisena on Sunday announced a ban on face covering, a week after suicide bombings that killed 253 people.
The restriction will take effect from Monday, his office said in a statement.
"The ban is to ensure national security... No one should obscure their faces to make identification difficult," the statement said.
Muslims in the majority Buddhist nation account for about 10 percent of its 21 million population.
Only a small number of Siri lankan women wear the niqab.