Art of Fighting (1992) by SNK was seemingly the first fighting game to have special attacks that could only be performed by consuming meter from a 'special gauge'. (Under the lifebar in this case.)

But I wonder what the oldest videogame you can think of to have this is?

And I'm specifically thinking of a special gauge that can be replenished through an active action by the player. (Such as a charge up animation like in Dragonball, or by attacking.)

So probably not something like an MP gauge to cast spells in an rpg.
Because those are typically replenished by potions. Same for the hearts in Castlevania.

I feel like SMB2/3 would have an attack like that…not sure.

Punch-Out! Would certainly fit the bill. You get stars from hitting your enemy at certain times, and then use those stars for his powered up uppercut. It is not exactly a meter, but that's just a visual thing. It could have just as easily been a three segment meter instead of stars. That is the earliest I can think of.

Not sure about Mario 2, but in Mario 3 there was a bar at the bottom that fills up as you run. And goes down if you stop running.

That might be close enough. But it depletes on its own when you stop running, and doesn't get spent when you perform the move (flying). So I'll see what else people may find.

Yeah the stars are exactly that. You build them up and then cash them out for a special attack.

Earliest release I can see is September 18, 1987.

Hmm Punchout was mentioned. Same year but R-Type has a charge shot.

Exerion (1983) has a "charge" shot whose ammo gets replenished by killing enemies with the normal shot.

Gradius 1 (1985) is my first I guess. "Power Meter" is not the typical meter, but the function is fairly similar.