NewbieCee

Hello

I have booked a round trip ticket from Los Angeles to Arlanda from
June 8, 2016 to October 10, 2016.

I do not plan to leave the Arlanda airport, but upon my arrival, I will be boarding a plane from Arlanda to Santorini on a separate flight ticket.

I understand that my flight itinerary exceeds the 90 days that U.S citizena are allowed to travel without applying for a long term visa; but I do not have the intention of staying in the Schengen Zone for more than 90 days.
I have plans, but have not booked, tickets to Dublin or London.

My question is, will my roundtrip ticket prevent me from entering Europe?
Also, will I need to go through immigration in Arlanda if my connecting flight to Greece is in the same terminal? So would I be given a stamp in my passport in Greece or in Sweden?

All the help would be appreciated, I made the mistake of not checking the visa regulations first

fassy

No, they do not care/check your in- and outbound flights. You have to make sure to stay within the allowed time-frame ruled by your visa-free entry into Schengen. If at some point in your travel you exit and re-enter Schengen, like going to Dublin or UK, they will see how many days you have stayed and how many you are still allowed to stay. If you exceeded your limit, they will deny entry.

Yes, you will directly after exiting the plane walk to the Schengen immigration passport control.

In Sweden. If you have checked baggage and the airlines do not interline you will need to exit the T5 airside zone, pick up your bags, re-check them and clear security again.