Microsoft Windows XP

 

C:\Documents and Settings\{user}\Application Data\Opera\Opera\
C:\Documents and Settings\{user}\Local Settings\Application Data\Opera\Opera\cache\

Microsoft Windows Vista / 7 / 8

 

C:\Users\{user}\AppData\Roaming\Opera\Opera\
C:\Users\{user}\AppData\Local\Opera\Opera\cache\

Apple Macintosh OS X

 

/Users/{user}/Library/Opera/
/Users/{user}/Library/Caches/Opera/cache/

GNU / Linux

 

/home/{user}/.opera/
/home/{user}/.opera/cache/