Yes, but only in a few countries. You can use PayPal in the UK, Denmark, Spain, Germany and Sweden - at the moment. New countries are added to this list from time to time, so keep an eye out.
The next step is to find a casino that actually accepts both PayPal deposits and players from your country of residence.
UK players can deposit with PayPal at William Hill, while other European customers should be able to use 888 Casino and Party Casino.