Should you salute a superior officer when you and/or the superior officer are not in uniform?

Damn right. Valor is valor in or out of uniform.

If I don't hyperventilate and pass out first, I will render the sharpest salute this broken old body can muster.

Lt Col Bubba Edwards Best answer seen on the internet Sir!

I would never salute an officer in civilian clothes just because of OPSEC. You never know who's watching. MoH recipient on the other hand, I've never had the privilege and honor of meeting one, but if I ever do, I would render a salute to an outstanding hero, anywhere, any place, at any time.

SSG, Agree with your “old school” analogy. I have no idea why everyone makes such a big deal out of this. I swear it seems some are even making up their own twist on what the Army, Navy, Marines, or Air Force regulations actually say. It is real simple show military curtesy where ever you are. If you are in uniform solute for crying out load it is not going to kill you. By now in your career it should be second nature and if it is not maybe you need to find another career field. Get that chip off of your shoulders and get on with your jobs. You know SSG things were a lot simpler back in the “old days” when one did not have to worry so much about trivial BS.

That's how I was trained. If it's on base definitely, especially if it's someone that you know (or should know) who they are without the uniform, like the Full Bird.

Out in town? It's a new world out there these days might not be safe anymore!

This is what I was taught as a young Soldier way back in the last century, if you recognize the officer, especially to be one of your unit's, then you salute them.

That is what I was always taught as well Chief.  Practically speaking however, the only senior officers I would salute out of uniform were my BN and BDE commanders.  But I would not dress down a subordinate who saluted me out of uniform.