The actor, who plays hero Jamie Fraser in the hit fantasy-history soap, tweeted: “Disgusting, childish imbeciles... I cannot believe we are being led out of Europe by this bunch of flag waving buffoons. Sickening.”
The Scotsman newspaper reports that his comment received almost 6,000 likes on the social media site.
Responses included messages from the USA, with one woman commenting: “Oh Sam. You now have an inkling of how some of us in the US have been feeling these last three years. It just never seems to end. My sincere condolences.”
Responder Lucy Sharvet agreed, writing: “They are idiots and they think that business will go on just as usual. Scotland needs to be independent or it will get dragged into a huge financial mess.”
Nancy Staack added: “Believe me, we feel for you. Fighting for our lives and democracy here.”