Since I found “is alexander skarsgard circumcised” in the search terms for fuzzypinkslippers.com, I thought I might ought to answer it. Apparently, he is not. Circumcision is mainly done in Africa and the Middle East. There are some western countries where it is more prevalent than others, i.e. America and Canada, where around 80% and 30% of the male population is circumcised. In some countries, including his native Sweden, bans on future circumcisions have been proposed. Even before the proposed ban, circumcision was rarely practiced there, so there is a very strong likelihood that the SkarsPenis has a foreskin.
For the record, I learned about this after the airing of “Radioactive”, the finale for Season 6 of True Blood. Someone sent in a question about it on Fuck Yeah Eric Northman, which led to a debate, and someone pointed out that circumcision isn’t as much of a thing in other western cultures as it is in America.