You can WWOOF in more than 120 countries world wide; it's quite possible there are hosts in your own country! Why not try it on your home ground first?
You can see the complete list of destinations at this page.
Please note that in the countries where there is a national WWOOF organisation in place you’ll need to purchase a membership for each one of those countries.
The countries without a national WWOOF organisation are listed on WWOOF Independents, managed by the Federation of WWOOF Organisations. The WWOOF Independents membership offers access to hosts across 80+ countries, with fewer hosts per country than those typically available through national WWOOF organisations.