how can I know which Gmail account was on my Android device? I had a Gmail account active on my Samsung S3. I made backup of contacts , and I uploaded them on my Google Drive account. I later did factory reset on the device, and I can't recall which Gmail account was setup on my device!

Is there anyway that I can come to know which Gmail account was on my Android device?
Go to Android Device Manager on your PC and log in with every Google account you have and check what account has your phone in it.
In Android Device Manager just log in, check for the device, if not there, try with a different account.  

Screenshot:



Android Device Manager: click here.

Hope my answer helps.