Recorded in surviving Polish records since the mid 19th century, as well as USA and the British Isles, this interesting surname is almost certainly a rare combination of nationalities including German, Polish and Slav. We have eliminated unlikely sources of the name particularly Irish. Research across the whole spectrum of Irish surnames shows no link. We have also eliminated major countries such as England, France, and Italy. Before the year 1800 there was virtually no mass education even in the more advanced countries, and only about one in ten of a population could do much more than write their name. Not surprisingly over the seven centuries since 'surnames' were invented, the majority of 'names' have undergone a metamorphis, and particularly in countries subject to political upheaval such as Poland, Prussia, and to some extent Russia. Surprisingly perhaps this surname when it 'emigrated' to America did not change, or if it did any 'new' spellings, have not been identified. At least one major family search company on the internet claims that this surname is ONLY recorded in the USA. This is clearly not correct. When fixed spelling surnames first appeared, people were often given them based on where they lived (or had lived), or their job descriptive. A study of this surname suggests it may be a version of the German 'Ock(er)', the name of a river in the Harz Mountains famous for its salmon. The suffix - oy is not recognised, suggesting a misspelling of the Slavonic -ov meaning 'son of'. Examples of recordings include Adam Okroy given as being born in Danzig, in 1856. This free state claimed by Germany, is now known as Gdansk, in Poland. The earliest recordings in any form are believed to be Okker zu Eblingen, Germany, in 1331, and Ocker zu Niederbuhl also Germany, in 1400.