Hello, Is it permissible to buy popcorn from a non Jewish cinema since popcorn in itself is normally kosher?

Shalom, Thank you for your question. Although questions of whether a product is kosher or not should generally be answered by kashrut organizations that are familiar with the particular situations in every case - none the less I did some research and found that the halacha is not to eat popcorn sold without kosher supervision. On one of the major kashrut sites (Star-K) it writes as follows "Concession Stand Popcorn - Many are under the assumption that one may purchase popcorn at the concession stand of various entertainment and sports venues. Unless that stand is under a reliable hashgacha, which is highly unlikely, this is absolutely incorrect. Popcorn is made with hot oil, which always needs hashgacha. Even if the current oil being used is kosher, there is no guarantee that a non- kosher oil or flavoring was not previously used, rendering the equipment and all subsequent popcorn not kosher." Blessings.