Historic legislation to allow Sunday trading has passed WA Parliament today.

All shops, including major supermarkets and department stores, in Perth metropolitan area will be able to open 11am-5pm each Sunday.

The change is expected to begin in August, although the government will not announce a formal starting date for another few weeks.

Minister for Commerce Simon O'Brien said the change was an historic moment for consumers and businesses.

"The move to give all retailers the right to open their doors on a Sunday was a key plank of this Government's commitment to bring trading hours into the 21st century," he said.