It looks like the answer is no (at least from within Gmail).
Is there any way to send an email to everyone in a Google Circle from Gmail? Or create a Contact Group from Circle?
gmail;google plus
Using Google Contacts PreviewGo to http://contacts.google.com/preview.Click on Circles.Click on the circle you want to send the email.Click on the envelope icon on the top of the circle members list.A compose email window will show up with all the circle members in the TO field.