What is the correct way to stress the Russian surname Иванов? I have seen both Ивано́в and Ива́нов.
Ивано́в is much more common although some Ivanovs prefer to be called
There is also the possessive adjective
Ива́нов день (Kupala Night).
I would say, if you are sure Ива́нов is a surname - then it most probably not Russian one but some West-Slavic (Bulgarian?).
And even more probable, that Ива́нов was not surname, it was a genitive case of plural of Иван first name.
- Ива́н => Ива́ны => Ива́нов
- John => Johns => of Johns
UPD by Yellow Sky: Ива́нов can also be a nominative case singular possessive adjective (John's), like мамин, Серёжин, etc. Cf. "Ива́нов день".