Are you asking just in the context of the American presidency? Or are you talking about broader history? If the latter, then I could answer you by saying that Diocletian (AD 245-313) retired of his own will from being Emperor in AD 305. Reportedly people even came back to him begging to take up the title of Emperor again, but he refused. If the former question, then I'm afraid I'm going to have to leave that to another's expertise.

An excellent example would be Cincinnatus. He served as consul of Rome (essentially the highest order of power) in 460 BC, then retired and went back to his farm. Two years later in time of a war crisis, he was elected dictator, who had immense powers over the armies that is meant to be temporary. Once everything settled down and Rome was back in peace, he went "back to the farm" akin to Washington and relinquished his power. He's celebrated especially for that reason. Twice he was the most powerful man in Rome and he served his civic duty for only the time that was required. You will often hear comparisons of Washington and Cinncinatus in discussions about how Washington left his position of power.

I'd love to add some sources, but I'm on mobile at the moment. The Wikipedia article on him has a pretty decent biography, but there are better ones that I read while studying Latin in school.

Livy provides an extensive account of his life in this translation:
http://courses.cvcc.vccs.edu/history_mcgee/courses/his101/Source%20Documents/wc1d11.htm

Lucius Cornelius Sulla was the first Roman to conquer Rome by military force, killed hundreds of Romans of the ruling classes, confiscated enough wealth to fill Rome's Treasury, re-wrote Rome's constitution to make Rome a stable and traditionally governed city again, had total absolute power over Rome for two years... and stepped down voluntarily as dictator (absolute unquestioned ruler of Rome) and resigned to the country. He left Rome in a scandalous parade of prostitutes, dancers, and actors - complete with his younger male lover, an actor named Metrobius, with whom he lived out the rest of his days (only another year or so).

Not sure if it fits your question but in France the General De Gaulle was known as a President for that kind of thing basically saying "oh you don't like the way I do things? Okey I quit we'll see how you perform without me then".

It caused him to disappear completly from the political landscape in 1946 when the parliament thought the executive was too strong and tried to pass a bill evening the things a bit.

He came back in power in 1958 and put an end to Algeria war by organizing a referendum allowing the Algerians to choose whether they wanted to stay French or not, shafting his supporters who for the most part wanted Algeria to remain French. In 1969 he organizes a referendum on a reform of the senate and quits when the French people answer no to it.