Most young foreigners seeking jobs in Greece find work in bars in tourist areas. Generally, bar owners are looking for people who speak the languages of the tourists coming to a specific area. If you're looking for a job in Greece, your best bet is to go where your fellow citizens tend to congregate. The Ionian islands attract Brits and some Italians; Crete has a heavy concentration of German travelers; Rhodes is another island popular with the British.
Americans go everywhere but frequently are found on Crete, Santorini, and Mykonos. Can't tend bar or wait tables? Here's more information on working as a club promoter in Greece.
The Legality of Getting a Job in Greece
EU citizens can legally work in Greece. Non-EU citizens are unlikely to be able to work legally in Greece at part-time and short-term positions. If you are going for a job with a major international corporation, they will assist you with the legalities of working in Greece.
The Reality of Getting a Summer Job in Greece
Many part-time, short-term jobs in Greece are for places that don't want to pay their full share of employment taxes. Even EU citizens may find themselves being offered work that is paid "under the table". The risk on these jobs is that you can be arrested and sent home and denied entry to Greece in the future. And in these situations, an employee may have virtually no options for getting their pay if the owner defaults on it.
Job Competition in Greece
Due to currency issues and pay rates at home, some nations have an abundance of young, often well-educated people who want to spend a summer in Greece. Lately, many employees are from Poland, Romania, Albania, and former Soviet-bloc nations. To many of them, the low pay rates in Greece may be a bit better than what they would find at home and they will often work harder, and longer, than their counterparts in other nations.
There are also job-placement agencies actively recruiting from these countries and making it easy for workers to get to and from Greece. Many come back year after year.
What Will Your Summer Job in Greece Pay?
If you're thinking of equivalent pay to what you would get for a similar job back home, think again. Hourly wages are often as low as 2 or 3 Euro, and some places may even expect you to work for tips alone. Others may (illegally) demand a share. While service jobs may benefit from tips, in most cases it still will not equal the pay rates back home.
Some summer jobs in Greece will provide a place to stay and some food, and if that's the case, surviving on the low wages is at least possible. In places like Ios, there are cheap hotels which rent shared rooms to summer workers for 14 Euro or so a night.
What Kind of Hours Will You Work in Greece?
Many summer jobs in Greece are just that - summer jobs. Often employers will expect an employee to work literally every day of the summer season, often for ten or twelve hours a day.
I'm Not Going to Wait Tables - I'm Going to Teach English!
Be cautious. There are a number of places suggesting that you can take a brief training course with them in Greece at your expense and then go teach English at a job they help you find.
Some of these are scams, plain and simple. There is no shortage of English-speaking people in Greece, and English is taught in the schools starting in third grade. Legitimate job opportunities for teaching English are relatively few, and will usually go to credentialed teachers and others with extensive or specialized experience rather than to a young and casual native speaker of English.