International Orthodox Christian Charities – a
The American Hellenic Educational Progressive Association (a
The World Council of Hellenes Abroad (a
EDIT: I Help Greece has been set up to handle international donations via credit card directly into the fund to aid fire-stricken areas set up by the Ministry of Economy and Finance. This account is intended to assist fire victims and restore materials damaged.
From within Greece you can make donations at any bank into account number 2341103053.