People in Renfrewshire and East Dunbartonshire are now not allowed to host or visit other households indoors.
The restriction on gatherings in people’s homes has also been extended in Glasgow, East Renfrewshire and West Dunbartonshire for at least another week.
The measures came into force for the latest two local authorities from midnight, amid an increase in coronavirus cases in the west of Scotland in recent weeks, mainly driven by private household gatherings.
A total of 78 new cases of the virus were reported on Monday in Greater Glasgow and Clyde and 92 on Sunday.
People can still meet different households outside, including in gardens, and in hospitality settings, providing existing Scottish Government guidance is followed.
That means no more than five households and 15 people meeting outdoors or three households and eight people meeting in a hospitality setting.
First Minister Nicola Sturgeon said: “Over recent weeks, we have seen a continued increase in new Covid-19 cases in the Greater Glasgow and Clyde health board area.
“Having looked at where cases are being identified, the advice from the public health experts managing this outbreak is that restrictions on indoor gatherings should be extended to Renfrewshire and East Dunbartonshire and continue for at least a further seven days in Glasgow, East Renfrewshire and West Dunbartonshire.
“I understand this will not be welcome news for people living in these areas but it is necessary to help us limit the spread of Covid-19. Acting now gives us the time and the space to protect people and get more control over the virus.”