Have witches ever been executed by the Eastern Orthodox Church?

Specifically no. No witches were recorded in orthodox tradition, not even as legends or myths. If there were ever witches there would be in isolated places, and again as others said before, the clergy would try to make them confess and finally repent with peaceful meanings.

Well, in fact there was a period that the Greek Orthodox church (with the guidance of the emperor of course) committed a "witch-hunting" staff. It was the period of iconomachy (it lasted almost a century) and during the crisis the iconoclasts burned holy icons and many iconophile texts and books, because they believed that god and saints cannot be iconized (probably influenced by Islam). Many monks, icon painters, and common people were tortured, maimed, exiled, or even executed for painting or even possessing icons. It was a situation quite similar to witch-hunting. But the motivations for iconomachy were clearly political, not religious. No other "witch-hunting situation" ever developed in the Orthodox East. If you ask me why, the answer will be: The land where Orthodoxy was ingrained was the Eastern Roman Empire (now called the Byzantine Empire). Its capital was Constantinople, originally called Nova Roma (New Rome). There were libraries, universities, and schools; the dark ages was never actually experienced there before 1453. So it makes sense that people would be (a little) more open-minded there than they were in the West.

Yes, they've been. Less but still. Started in Byzantium, but the most huge in Muscovy (Russia), especially after the Stoglavy Sobor of Russian Orthodox Church. Of course, we don't know such a huge scale of victims as in Germany or France (but great amount of such an information might be unknown because of lack of paperwork in Early Modern Russian courts). And we should keep in mind that huge witch-hunts all over Europe were held in secular (not church!) courts

In the Orthodox Church, people who have practised witchcrat, or attempted to do so, are urged to confess that as a sin. Attempting to harm other people, whether by natural or "supernatural" means, is an indication of malice, which is definitely sinful,

There is more detail in my article on Christian responses to witchcraft and sorcery.

Someone else referred to that above, but the link has changed.

Frankly, the more you know the history of the Orthodox Church, the more you would be inclined to say that they would never have executed witches. In fact great portions of the Eastern Orthodox Churches history, is when they have been the ones being executed, whether by pagans or heretics. In fact if someone told me that the Orthodox had executed witches, I would probably think that it was some heretical branch.

According to this link:

the Protestant reformers often agreed with Rome, that witches were a clear and present danger. All four of the major western Christian "churches" (Roman Catholic, Lutheran, Calvinist, Anglican) persecuted witches to some degree or another. (Eastern Christian, or Orthodox Churches carried out almost no witch hunting).

I would say that if the Orthodox Church ever found a "witch", they would have tried to purify him/her, and bring that person (back) to the Church. Also, no one was allowed to kill anyone, except as a soldier. Perhaps some corrupt Emperors would have done this, (In fact I know they did), but the Church Fathers would confront that emperor to his face and tell him he did wrong (though this is not an example with witches, I had to call to mind the story of Ambrose and Theodosius).

So if you have any doubts and questions, please tell me. I believe that the Eastern Church would never have done this, unless someone in authority was corrupted.

But then we are all sinners.