Brian Cox "wouldn't want" a knighthood.
The 'Succession' actor - who was an active member of the campaign for Scottish independence - was awarded a Commander of the Order of the British Empire (CBE) honour in 2002 but insisted he won't accept anything higher and will "never" be a sir.
Asked if he'd accept a knighthood, he said: "I wouldn't want to do that. I'll never be 'sir'."
And the 73-year-old actor admitted he regrets accepting the CBE and only did so because he is "fickle".
He is quoted by the Daily Mail newspaper's Sebastian Shakespeare as saying: "I did it at a time when I should have thought better but I accepted it because I'm fickle.
"When I became a CBE, my excuse was that I have a royalist sister and I have a republican sister so I thought "Well, my royalist sister will be happy for that". She couldn't give a s**t, but that was my justification."
Meanwhile, the 'X-Men' actor was recently dropped as patron of OAP centre Mid-Lin Daycare Centre after admitting he uses marijuana, leaving bosses "shocked and disappointed".
Mid-Lin Daycare Centre chairwoman Joyce McIntosh said: "Dundee is drug-ridden we just can't support Brian's views on cannabis. We are shocked and disappointed. I couldn't actually believe it when I read the papers - he has a CBE and all these awards and honorary positions, and next thing, we're seeing that he's telling people to get stoned. It's absolutely ridiculous and it's setting a bad example for young people."
Brian - who is married to Nicole Ansari - stood by his comments and wished the OAP centre well.
He shared: "I am sorry to hear that Mid-Lin Day Care Centre were shocked and disappointed by my comments regarding marijuana, which were actually made in good humour.
"To clarify, I am a firm believer in the medicinal benefits of marijuana and have partaken in its use in places where it is legal to do so. I wish Mid-Lin the best in all their future endeavours."